Version Control with Git - Politecnico di...
55
Giuseppe Massari [email protected] Version Control with Git Advanced Operating Systems [email protected]
Transcript of Version Control with Git - Politecnico di...
![Page 1: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/1.jpg)
Giuseppe Massarigiuseppemassaripolimiit
Version Control with GitAdvanced Operating Systems
giuseppemassaripolimiit
Advanced Operating SystemsGiuseppe Massari
552Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Changes management Working with branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
553Why using version control tools
Single developer Do we need to keep track of the history of changes in a software project How to effectively ndash keep track of store ndash such changes
Copying sources into new directories (eg MyProject_v20151006_) What about disk occupancy
Multiple developers How to merge changes and additions coming from other developers
Manual copy-and-paste for each changed file Cloud storage (eg Dropbox)
How to keep track of whos the author of a change Mmm maybe looking for mails with source code attached
Advanced Operating SystemsGiuseppe Massari
554Why Git
Distributed approach The entire project history database is local
rarr Faster browsing among the changes rarr No traffic generated on the network rarr Changes can be committed locally before sharing rarr Higher reliability Central server DOWN is not an issue
Integrity mechanisms Every change is tracked SHA-1 checksum
40-character string composed of hexadecimal characterscalculated based on the contents of a file or directory structure in GIT
Advanced Operating SystemsGiuseppe Massari
555First steps
Help The command-line usage of Git is based on commands To get help about a specific command syntax
If no command is given an overview of the most common Git commands is returned
$ git help [command]$ git help [command]
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
Advanced Operating SystemsGiuseppe Massari
556First steps
Configuration Setup user name mail and preferences
Configuration ldquolevelsrdquo reference three possible configuration files
First configuration steps
$ git config ltlevelgt ltoptiongt value$ git config ltlevelgt ltoptiongt value
$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit
--system etcgitconfig System wide scope
--global ~gitconfig~configgit
User scope
--local gitconfig Local project scope
Advanced Operating SystemsGiuseppe Massari
557First steps
Basic concepts Repository
Concretely (sub)directory where in Git stores metadata and object database for the project (git)
Working directoryA checkout of one version of the project
The tracked files pulled out of the compressed database in the git directory
Staging area The set of selected changes ready to be committed In practice a file (ldquoINDEXrdquo) contained in git directory storing information about the changes to track in theforthcoming next commit
Workingdirectory
StagingArea
Repository(git directory)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 2: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/2.jpg)
Advanced Operating SystemsGiuseppe Massari
552Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Changes management Working with branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
553Why using version control tools
Single developer Do we need to keep track of the history of changes in a software project How to effectively ndash keep track of store ndash such changes
Copying sources into new directories (eg MyProject_v20151006_) What about disk occupancy
Multiple developers How to merge changes and additions coming from other developers
Manual copy-and-paste for each changed file Cloud storage (eg Dropbox)
How to keep track of whos the author of a change Mmm maybe looking for mails with source code attached
Advanced Operating SystemsGiuseppe Massari
554Why Git
Distributed approach The entire project history database is local
rarr Faster browsing among the changes rarr No traffic generated on the network rarr Changes can be committed locally before sharing rarr Higher reliability Central server DOWN is not an issue
Integrity mechanisms Every change is tracked SHA-1 checksum
40-character string composed of hexadecimal characterscalculated based on the contents of a file or directory structure in GIT
Advanced Operating SystemsGiuseppe Massari
555First steps
Help The command-line usage of Git is based on commands To get help about a specific command syntax
If no command is given an overview of the most common Git commands is returned
$ git help [command]$ git help [command]
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
Advanced Operating SystemsGiuseppe Massari
556First steps
Configuration Setup user name mail and preferences
Configuration ldquolevelsrdquo reference three possible configuration files
First configuration steps
$ git config ltlevelgt ltoptiongt value$ git config ltlevelgt ltoptiongt value
$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit
--system etcgitconfig System wide scope
--global ~gitconfig~configgit
User scope
--local gitconfig Local project scope
Advanced Operating SystemsGiuseppe Massari
557First steps
Basic concepts Repository
Concretely (sub)directory where in Git stores metadata and object database for the project (git)
Working directoryA checkout of one version of the project
The tracked files pulled out of the compressed database in the git directory
Staging area The set of selected changes ready to be committed In practice a file (ldquoINDEXrdquo) contained in git directory storing information about the changes to track in theforthcoming next commit
Workingdirectory
StagingArea
Repository(git directory)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 3: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/3.jpg)
Advanced Operating SystemsGiuseppe Massari
553Why using version control tools
Single developer Do we need to keep track of the history of changes in a software project How to effectively ndash keep track of store ndash such changes
Copying sources into new directories (eg MyProject_v20151006_) What about disk occupancy
Multiple developers How to merge changes and additions coming from other developers
Manual copy-and-paste for each changed file Cloud storage (eg Dropbox)
How to keep track of whos the author of a change Mmm maybe looking for mails with source code attached
Advanced Operating SystemsGiuseppe Massari
554Why Git
Distributed approach The entire project history database is local
rarr Faster browsing among the changes rarr No traffic generated on the network rarr Changes can be committed locally before sharing rarr Higher reliability Central server DOWN is not an issue
Integrity mechanisms Every change is tracked SHA-1 checksum
40-character string composed of hexadecimal characterscalculated based on the contents of a file or directory structure in GIT
Advanced Operating SystemsGiuseppe Massari
555First steps
Help The command-line usage of Git is based on commands To get help about a specific command syntax
If no command is given an overview of the most common Git commands is returned
$ git help [command]$ git help [command]
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
Advanced Operating SystemsGiuseppe Massari
556First steps
Configuration Setup user name mail and preferences
Configuration ldquolevelsrdquo reference three possible configuration files
First configuration steps
$ git config ltlevelgt ltoptiongt value$ git config ltlevelgt ltoptiongt value
$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit
--system etcgitconfig System wide scope
--global ~gitconfig~configgit
User scope
--local gitconfig Local project scope
Advanced Operating SystemsGiuseppe Massari
557First steps
Basic concepts Repository
Concretely (sub)directory where in Git stores metadata and object database for the project (git)
Working directoryA checkout of one version of the project
The tracked files pulled out of the compressed database in the git directory
Staging area The set of selected changes ready to be committed In practice a file (ldquoINDEXrdquo) contained in git directory storing information about the changes to track in theforthcoming next commit
Workingdirectory
StagingArea
Repository(git directory)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 4: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/4.jpg)
Advanced Operating SystemsGiuseppe Massari
554Why Git
Distributed approach The entire project history database is local
rarr Faster browsing among the changes rarr No traffic generated on the network rarr Changes can be committed locally before sharing rarr Higher reliability Central server DOWN is not an issue
Integrity mechanisms Every change is tracked SHA-1 checksum
40-character string composed of hexadecimal characterscalculated based on the contents of a file or directory structure in GIT
Advanced Operating SystemsGiuseppe Massari
555First steps
Help The command-line usage of Git is based on commands To get help about a specific command syntax
If no command is given an overview of the most common Git commands is returned
$ git help [command]$ git help [command]
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
Advanced Operating SystemsGiuseppe Massari
556First steps
Configuration Setup user name mail and preferences
Configuration ldquolevelsrdquo reference three possible configuration files
First configuration steps
$ git config ltlevelgt ltoptiongt value$ git config ltlevelgt ltoptiongt value
$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit
--system etcgitconfig System wide scope
--global ~gitconfig~configgit
User scope
--local gitconfig Local project scope
Advanced Operating SystemsGiuseppe Massari
557First steps
Basic concepts Repository
Concretely (sub)directory where in Git stores metadata and object database for the project (git)
Working directoryA checkout of one version of the project
The tracked files pulled out of the compressed database in the git directory
Staging area The set of selected changes ready to be committed In practice a file (ldquoINDEXrdquo) contained in git directory storing information about the changes to track in theforthcoming next commit
Workingdirectory
StagingArea
Repository(git directory)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 5: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/5.jpg)
Advanced Operating SystemsGiuseppe Massari
555First steps
Help The command-line usage of Git is based on commands To get help about a specific command syntax
If no command is given an overview of the most common Git commands is returned
$ git help [command]$ git help [command]
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
usage git [--version] [--help] [-C ltpathgt] [-c name=value] [--exec-path[=ltpathgt]] [--html-path] [--man-path] [--info-path] [-p|--paginate|--no-pager] [--no-replace-objects] [--bare] [--git-dir=ltpathgt] [--work-tree=ltpathgt] [--namespace=ltnamegt] ltcommandgt [ltargsgt]
The most commonly used git commands are add Add file contents to the index bisect Find by binary search the change that introduced a bug branch List create or delete branches checkout Checkout a branch or paths to the working tree clone Clone a repository into a new directory commit Record changes to the repository
Advanced Operating SystemsGiuseppe Massari
556First steps
Configuration Setup user name mail and preferences
Configuration ldquolevelsrdquo reference three possible configuration files
First configuration steps
$ git config ltlevelgt ltoptiongt value$ git config ltlevelgt ltoptiongt value
$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit
--system etcgitconfig System wide scope
--global ~gitconfig~configgit
User scope
--local gitconfig Local project scope
Advanced Operating SystemsGiuseppe Massari
557First steps
Basic concepts Repository
Concretely (sub)directory where in Git stores metadata and object database for the project (git)
Working directoryA checkout of one version of the project
The tracked files pulled out of the compressed database in the git directory
Staging area The set of selected changes ready to be committed In practice a file (ldquoINDEXrdquo) contained in git directory storing information about the changes to track in theforthcoming next commit
Workingdirectory
StagingArea
Repository(git directory)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 6: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/6.jpg)
Advanced Operating SystemsGiuseppe Massari
556First steps
Configuration Setup user name mail and preferences
Configuration ldquolevelsrdquo reference three possible configuration files
First configuration steps
$ git config ltlevelgt ltoptiongt value$ git config ltlevelgt ltoptiongt value
$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit$ git config --global username Giuseppe Massari$ git config --global useremail giuseppemassaripolimiit
--system etcgitconfig System wide scope
--global ~gitconfig~configgit
User scope
--local gitconfig Local project scope
Advanced Operating SystemsGiuseppe Massari
557First steps
Basic concepts Repository
Concretely (sub)directory where in Git stores metadata and object database for the project (git)
Working directoryA checkout of one version of the project
The tracked files pulled out of the compressed database in the git directory
Staging area The set of selected changes ready to be committed In practice a file (ldquoINDEXrdquo) contained in git directory storing information about the changes to track in theforthcoming next commit
Workingdirectory
StagingArea
Repository(git directory)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 7: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/7.jpg)
Advanced Operating SystemsGiuseppe Massari
557First steps
Basic concepts Repository
Concretely (sub)directory where in Git stores metadata and object database for the project (git)
Working directoryA checkout of one version of the project
The tracked files pulled out of the compressed database in the git directory
Staging area The set of selected changes ready to be committed In practice a file (ldquoINDEXrdquo) contained in git directory storing information about the changes to track in theforthcoming next commit
Workingdirectory
StagingArea
Repository(git directory)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 8: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/8.jpg)
Advanced Operating SystemsGiuseppe Massari
558First steps
Basic workflow
Workingdirectory
StagingArea
Repository(git directory)
Checkout a project branch
Stage changes
Commit changes
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 9: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/9.jpg)
Advanced Operating SystemsGiuseppe Massari
559Local repository management
Your first Git repository Enter the new project directory Initialize the Git repository
This will create the git directory From now on you can trackchanges in our project committing them in the Git repository
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
$ cd ~DevelopmentMyProject$ git initInitialized empty Git repository in ~DevelopmentMyProjectgit
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
~DevelopmentMyProject git
branches config description HEAD hooks info objects refs
All the ldquomagicsrdquo behind Git is here
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 10: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/10.jpg)
Advanced Operating SystemsGiuseppe Massari
5510Local repository management
Your first Git repository Create some files and do you first commit
Now we have the very first step of our project history
$ touch maincpp$ git add maincpp$ git commit -s
$ touch maincpp$ git add maincpp$ git commit -s
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
$ git log
commit 8c837e5e223ee55bb9c9d1818fca67b8a365e94aAuthor Giuseppe Massari ltjoemassangagmailcomgtDate Fri Oct 16 135953 2015 +0200
Initial commit Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 11: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/11.jpg)
Advanced Operating SystemsGiuseppe Massari
5511Local repository management
Diff As we continue introducing changes we can list them for each file
If no files are specified all the changes for each file are shown
$ git diff [file-name]$ git diff [file-name]
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 12: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/12.jpg)
Advanced Operating SystemsGiuseppe Massari
5512Local repository management
Status After performing some changes we may want to have an overview of the project status
The command status recaps the status of the working directory and the staging area
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
On branch masterChanges to be committed (use git reset HEAD ltfilegt to unstage)
new file mainh
Changes not staged for commit (use git add ltfilegt to update what will be committed) (use git checkout -- ltfilegt to discard changes in working directory)
modified maincpp
Untracked files (use git add ltfilegt to include in what will be committed)
README
$ git status$ git status
Staging area
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 13: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/13.jpg)
Advanced Operating SystemsGiuseppe Massari
5513Local repository management
Commit What it is
A tracked change in the project new files or changes in already existing files When to do it
Whenever we consider the changes introduced as a ldquostablerdquo part of the project development
What TO commit Whatever can be considered a source file
What TO DO NOT commit Whatever is generated from source files
How to commit add files or changes in files to staging area and then commit
$ git add ltfilesgt$ git commit $ git add ltfilesgt$ git commit
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 14: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/14.jpg)
Advanced Operating SystemsGiuseppe Massari
5514Local repository management
How to make a ldquogoodrdquo commit Description
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
Model Power-thermal models support The purpose of this support is to providing a well-defined interface to powerthermal resource allocation policy hiding platform specific details A ModelManager allows the registration of platform-specific models according to the target platform selected Such models are implemented as derived classes of the base class Model Signed-off-by Giuseppe Massari ltgiuseppemassaripolimiitgt
A ldquotaglabelrdquo to easily identify the project module touched
A brief title to summarize the changes introduced
Authors signature (git commit -s)
An exhaustive explanation of what has been done and why
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 15: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/15.jpg)
Advanced Operating SystemsGiuseppe Massari
5515Local repository management
How to make a ldquogoodrdquo commit Include only consistent changes
A single source file can include changes having different goals Bug fixing Code refactoring New functionality implemented
Use git gui to be more productive
Select lines (also from different files) changed for the same single specific purpose
Right-click on changed lines Select ldquoStage lines for commitrdquo
$ git gui$ git gui
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 16: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/16.jpg)
Advanced Operating SystemsGiuseppe Massari
5516Local repository management
Log To recap the history of the project development
$ git log$ git log
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 7bb21c0837093be82d391ad9d03d5d8235193704Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180625 2015 +0200
[Main] Using a People object Added an instance of People object (joe) walking and greeting Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
commit 5124691db36e150b2839fd923b3ca71186b22fe6Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 180308 2015 +0200
[People] Class first version Including member functions Walk() and Greet() Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 17: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/17.jpg)
Advanced Operating SystemsGiuseppe Massari
5517Local repository management
Show To show commit details (description + changes)
$ git show [SHA1_number]$ git show [SHA1_number]
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
giuseppeplutone~DevelopmentTestGitTutorial$ git show 5552cefcommit 5552cefd12be253fd10c50cd03b64525eb0217f5Author Giuseppe Massari ltjoemassangagmailcomgtDate Mon Oct 19 172040 2015 +0200
[Main] First implementation The main function now prints a message Signed-off-by Giuseppe Massari ltjoemassangagmailcomgt
diff --git amaincpp bmaincppindex e69de29d9d9396 100644--- amaincpp+++ bmaincpp -00 +19 +include ltiostreamgt++int main(int argc const char argv[])++ stdcout ltlt Hello GIT World ltlt stdendl++ return 0++
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 18: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/18.jpg)
Advanced Operating SystemsGiuseppe Massari
5518Local repository management
Graphical front-ends
$ gitk --all$ gitk --all
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 19: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/19.jpg)
Advanced Operating SystemsGiuseppe Massari
5519Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git add
git commit
git init
Do changes
git diffgit statusgit show
Repeat
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 20: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/20.jpg)
Advanced Operating SystemsGiuseppe Massari
5520Local repository management
Undo commands How to ldquounstagerdquo changes already added to the staging area
$ git checkout filename$ git checkout filename
Workingdirectory
StagingArea
git add file
git checkout file
Just a step back without cleaning the changes in the sources
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 21: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/21.jpg)
Advanced Operating SystemsGiuseppe Massari
5521Local repository management
Undo commands How to clean out unstaged changes
Clean out all the (unstageduncommited) changes in the tracked files
How to ldquocorrectrdquo a commit
ldquoOpenrdquo the current commit and allows us to addremove fileslines or modify the commit message
It overwrites the commit creating a new one (with a different SHA-1) Not recommended if the commit has been already pushed on the remote repository
Revert the changes of the specified commit Added lines become removed lines and viceversa
$ git commit --amend$ git commit --amend
$ git revert SHA-1_number$ git revert SHA-1_number
$ git reset --hard$ git reset --hard
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 22: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/22.jpg)
Advanced Operating SystemsGiuseppe Massari
5522Local repository management
Branches In real projects the development history is far from progressing on a straight line
Split developers to work in parallel each focusing on specific features
Software versions targeting different versions following different paths
The concept of branch is all about this
By default the Git repository initializationcreates the master branch
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 23: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/23.jpg)
Advanced Operating SystemsGiuseppe Massari
5523Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master HEAD HEAD is basically a reference to the topmost commit on the current branch
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 24: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/24.jpg)
Advanced Operating SystemsGiuseppe Massari
5524Local repository management
Branches Creating (and switching to) a new branch
Initialcommit
d45e26
ee2e90
master
$ git checkout -b dev$ git checkout -b dev
master dev
dev
The new dev branch points to the same topmost master commit
Command checkout action is different in case the argument is a branch instead of a file name
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 25: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/25.jpg)
Advanced Operating SystemsGiuseppe Massari
5525Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
devc82dda
dev
The dev branch starts ldquogrowingrdquo
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 26: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/26.jpg)
Advanced Operating SystemsGiuseppe Massari
5526Local repository management
Branches Committing on top of a new branch
Initialcommit
d45e26
ee2e90
master
$ git commit $ git commit
master
c82dda
deva157dc
dev
The project history is slowly starting to show a ldquotreerdquo shape
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 27: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/27.jpg)
Advanced Operating SystemsGiuseppe Massari
5527Local repository management
Branches Switching back to master branch
Initialcommit
d45e26
ee2e90
master
$ git checkout master$ git checkout master
master
c82dda
deva157dc
dev
Once back to master the changes introduced in the last dev commits apparently ldquodisappearrdquo
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 28: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/28.jpg)
Advanced Operating SystemsGiuseppe Massari
5528Local repository management
Branches Merging master and dev branches
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
deva157dc
dev
Now if we switch between master and dev we would not see changes in the project
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 29: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/29.jpg)
Advanced Operating SystemsGiuseppe Massari
5529Local repository management
Branches Labels on commits
Initialcommit
d45e26
ee2e90
master
$ git tag -a v01 a157dc$ git tag -a v01 a157dc
master
c82dda
deva157dc
dev
The tag can be thought as a label to mark our releases and improve the git tree readability
v01
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 30: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/30.jpg)
Advanced Operating SystemsGiuseppe Massari
5530Local repository management
Conflicts In some cases merging branches may lead to conflicts
Initialcommit
d45e26
ee2e90
master
$ git merge dev$ git merge dev
master
c82dda
dev
a157dc
dev
479bMaster and dev branches include commits that touched the same lines of the same file
CONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the resultCONFLICT (content) Merge conflict in maincppAutomatic merge failed fix conflicts and then commit the result
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 31: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/31.jpg)
Advanced Operating SystemsGiuseppe Massari
5531Local repository management
Conflicts The status command reports the conflict in this way
To solve the conflict the conflict we need to open the files involved and check the content
Git automatically add ldquospecial linesrdquo into the file to identify the conflict and help us
$ git status dev$ git status dev
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
On branch masterYou have unmerged paths (fix conflicts and run git commit)
Unmerged paths (use git add ltfilegt to mark resolution)
both modified maincpp
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 32: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/32.jpg)
Advanced Operating SystemsGiuseppe Massari
5532Local repository management
Conflicts maincpp is the file containing the conflict
Lines 7-9 HEAD status changes in commit on top of current branch (master) Lines 9-10 changes coming from the merging branch (dev)
Resolution Make a choice about the lines to keep or deleted remove Delete special lines ldquoltltltlt===gtgtgtrdquo Add the files to the staging area (INDEX) Commit
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
7 ltltltltltltlt HEAD 8 stdcout ltlt Hello walking man ltlt stdendl 9 =======10 gtgtgtgtgtgtgt dev
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 33: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/33.jpg)
Advanced Operating SystemsGiuseppe Massari
5533Local repository management
Rebasing Move a branch on top of another
May lead to conflicts Do it as long as your are moving a local branch
$ git rebase master dev$ git rebase master dev
d45e26
ee2e90masterc82dda
a157dc
d45e26
ee2e90
c82dda
dev a157dc
master
dev
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 34: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/34.jpg)
Advanced Operating SystemsGiuseppe Massari
5534Local repository management
Stashing Temporarily hide current (uncommited) changes on a ldquostackrdquo
Useful in case of switching on a branch already including changes on files we currently working on
I can stack multiple stashed changes
To discard stashed changes
To resume the stashed changes
$ git stash save ldquoChanges about feature1 implementationrdquo$ git stash save ldquoChanges about feature1 implementationrdquo
$ git stash list$ git stash list
$ git stash drop stashN$ git stash drop stashN
$ git stash pop [stashN]$ git stash pop [stashN]
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 35: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/35.jpg)
Advanced Operating SystemsGiuseppe Massari
5535Local repository management
Basic work-flow in commands
Workingdirectory
StagingArea
Repository(git directory)
git checkout ltbranch_namegt
git add
git commit
git init
Do changesgit diffgit statusgit show
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 36: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/36.jpg)
Advanced Operating SystemsGiuseppe Massari
5536Local repository management
Work-flow example To manage the software release cycles we can design a work-flow by splitting bug fixing feature development and release-candidate versions in dedicated branches
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 37: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/37.jpg)
Advanced Operating SystemsGiuseppe Massari
5537Outline
Why using version control tools Why Git
First steps Getting help and configuration Basic concepts
Local repository management Initialization Change management Branches Conflicts management
Shared remote repository management Cooperative development
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 38: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/38.jpg)
Advanced Operating SystemsGiuseppe Massari
5538Remote repository management
Cooperative development Several developers working on the same project
Joe Simon Fred
Project
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 39: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/39.jpg)
Advanced Operating SystemsGiuseppe Massari
5539Remote repository management
Remote repository work-flow
Workingdirectory
StagingArea
Local repository
git checkout ltbranch_namegt
git add
git commit
Remote repository
git clone
git fetchpull
git push
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 40: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/40.jpg)
Advanced Operating SystemsGiuseppe Massari
5540Remote repository management
Basic commands To clone a project (from a remote repository)
To download all the changes from the remote repository New commits new branches new tags
To download changes and merge it in the current local branch Fetch + merge
To upload local changes to remote repository
$ git clone repository_path$ git clone repository_path
$ git fetch repository_name$ git fetch repository_name
$ git pull repository_name [branch_name]$ git pull repository_name [branch_name]
$ git push repository_name [branch_name]$ git push repository_name [branch_name]
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 41: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/41.jpg)
Advanced Operating SystemsGiuseppe Massari
5541Remote repository management
Cooperative development
Joe Simon Fred
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 42: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/42.jpg)
Advanced Operating SystemsGiuseppe Massari
5542Remote repository management
Cooperative development Joe starts a project tracking changes on a local repository
Joe Simon Fred
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
[Joe]$ git init[Joe]$ git add hellip[Joe]$ git commit hellip
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 43: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/43.jpg)
Advanced Operating SystemsGiuseppe Massari
5543Remote repository management
Cooperative development Joe adds a remote repository to the project
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git remote add origin gitmyserverorgjoemyprojgit[Joe]$ git remote add origin gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 44: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/44.jpg)
Advanced Operating SystemsGiuseppe Massari
5544Remote repository management
Cooperative development Joe shares its work by uploading its current git tree to the remote repository Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push -u --all origin[Joe]$ git push -u --all origin
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 45: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/45.jpg)
Advanced Operating SystemsGiuseppe Massari
5545Remote repository management
Cooperative development Simon and Fred clone the remote git repository so that they can contribute to the project Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit[Simon]$ git clone gitmyserverorgjoemyprojgit[Fred]$ git clone gitmyserverorgjoemyprojgit
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 46: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/46.jpg)
Advanced Operating SystemsGiuseppe Massari
5546Remote repository management
Cooperative development Simon fix bugs committing changes on a new branch (hotfix)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Simon]$ git checkout -b hotfix[Simon]$ git commit [Simon]$ git checkout -b hotfix[Simon]$ git commit
HEAD
HEADHEAD
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 47: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/47.jpg)
Advanced Operating SystemsGiuseppe Massari
5547Remote repository management
Cooperative development Fred implements a new feature committing changes on a new branch (feature1) Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git checkout -b feature1[Fred]$ git commit [Fred]$ git checkout -b feature1[Fred]$ git commit
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 48: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/48.jpg)
Advanced Operating SystemsGiuseppe Massari
5548Remote repository management
Cooperative development Fred and Simon upload their changes (branches)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git push origin feature1[Simon]$ git push origin hotfix[Fred]$ git push origin feature1[Simon]$ git push origin hotfix
HEAD
HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 49: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/49.jpg)
Advanced Operating SystemsGiuseppe Massari
5549Remote repository management
Cooperative development Joe updates its local repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git fetch origin[Joe]$ git fetch origin
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 50: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/50.jpg)
Advanced Operating SystemsGiuseppe Massari
5550Remote repository management
Cooperative development Joe merge the contributions in the project ldquomain linerdquo (ie master)
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix[Joe]$ git merge originfeature1[Joe]$ git merge originhotfix
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 51: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/51.jpg)
Advanced Operating SystemsGiuseppe Massari
5551Remote repository management
Cooperative development Joe uploads the (updated) master branch to the remote repository
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Joe]$ git push origin master[Joe]$ git push origin master
HEADHEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 52: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/52.jpg)
Advanced Operating SystemsGiuseppe Massari
5552Remote repository management
Cooperative development Simon and Fred synchronize their local repository with the remote
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[Fred]$ git fetch origin [Simon]$ git fetch origin[Fred]$ git fetch origin [Simon]$ git fetch origin
HEAD HEAD
HEAD
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 53: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/53.jpg)
Advanced Operating SystemsGiuseppe Massari
5553Remote repository management
Cooperative development Simon and Fred get the updated master
Git server
Joe Simon Fred
gitmyserverorgjoemyprojgit
(origin)
[FredSimon]$ git checkout master [FredSimon]$ git pull origin master[FredSimon]$ git checkout master [FredSimon]$ git pull origin master
HEAD HEAD HEAD
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 54: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/54.jpg)
Advanced Operating SystemsGiuseppe Massari
5554Extras
Cherry-pick How to import a single commit from a branch
Example a bugfix patch has been committed on a development branch
d45e26
ee2e90masterc82dda
a157dcbugfixes
d45e26
ee2e90
master
c82dda
a157dcc82dda
bugfixes
$ git cherry-pick ltcommit-SHA1gt$ git cherry-pick ltcommit-SHA1gt
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Page 55: Version Control with Git - Politecnico di Milanohome.deib.polimi.it/...media=teaching:aos:2017:aos_l2_version_control_with_git.pdf · [--git-dir=] [--work-tree=]](https://reader030.fdocuments.in/reader030/viewer/2022041210/5dd098dcd6be591ccb61c348/html5/thumbnails/55.jpg)
Advanced Operating SystemsGiuseppe Massari
5555Resources
httpsgit-scmcom httpswwwatlassiancomgit httpwwwtutorialspointcomgit
![Git LFS - acailly.github.io · $ git config --list [...] filter.lfs.clean=git-lfs clean -- %f filter.lfs.smudge=git-lfs smudge -- %f filter.lfs.process=git-lfs filter-process filter.lfs.required=true](https://static.fdocuments.in/doc/165x107/60bd0c0fa3a22721690a1c10/git-lfs-git-config-list-filterlfscleangit-lfs-clean-f-filterlfssmudgegit-lfs.jpg)
