INTRODUCTION TO GIT · DAVID PARSONS - INTRODUCTION TO GIT 12 The Staging Area (a.k.a Index) •...

INTRODUCTION TO GIT

DAVID PARSONS

DAVID PARSONS - INTRODUCTION TO GIT 2 DAVID PARSONS - INTRODUCTION TO GIT

Source Code Management Tools 1

DAVID PARSONS - INTRODUCTION TO GIT 3

•  Sourcecodemanagers(scm)a.k.a.versioncontrolsystems(vcs)

•  Allowforthecompletetrackingandarchivingofthemodifica=onsmadetoasetoffiles

•  Makecollabora=vedevelopmenteasier•  UsuallyexistonallplaBormsusingthe

commandlineoragraphicaluserinterface•  Areprimarilymeanttomanagetextfilesbut

canalsohandlebinaryfiles(e.g.images).However:donottrackanygeneratedfiles

•  Arenotadaptedformanagingbackups!


The«DropBox»case


Resolu=onusinganSCM


RepositoriesandRevisions

•  ARepository•  Containsthecompletehistoryofthe

project(i.e.alltherevisions)

•  Arevision(a.k.a.commitorversion)•  Isasnapshotofallthetrackedfiles•  Isusuallybasedupononeotherrevision•  Correspondstoaniden=fiedauthor•  Containsamessagethatexplainsthe

ra=onaleforthemodifica=onsintroducedbytherevisionandanyotherinfotheauthorconsidersrelevant

A1 B C

A2 B1 C

A B CRev1

Rev2

Rev3


Twofundamentalrules!

•  CommitoRen•  Keepcommitssmallandcommittogetheronlyrelated

changes

•  Writeclearandinforma=velogs•  Alogshouldenableitsreaderto:

1.  Iden=fyataglancethera=onalebehindthecommit2.  Havedetailedexplana=onifneeded

•  Templateforlogs(fromhUp://git-scm.com/book/ch5-2.html)

Short(50charsorless)summaryofchangesMoredetailedexplanatorytext,ifnecessary.Wrapittoabout72charactersorso.Insomecontexts,thefirstlineistreatedasthesubjectofanemailandtherestofthetextasthebody.Theblanklinesepara=ngthesummaryfromthebodyiscri=cal(unlessyouomitthebodyen=rely).


Git – Overview 2


•  Gitisadistributedversioncontrolsystem

•  Originalauthor:LinusTorvalds•  Firstversiondevelopedin~1weekaRersometroublewithBitKeeper(proprietarysolu=on)

•  Thereference:hUp://git-scm.com/•  Notoriouscompe=tors:svn,mercurial

Context


Workingcopy+Localrepo

Eachuserhas(onhisowncomputer):•  Hisownlocalrepository(storedin

the.gitrepository)•  Aworkingcopy(a.k.a.checkout)of

thetrackedfiles.

Youmaycheckoutanyrevision(commit)oftheprojectusingthecommand:git checkout <commit>

Thiswillpopulateyourworkingcopywiththecontentofthespecifiedcommit


TheStagingArea(a.k.aIndex)

•  “Paya0en1onnow”(gitbook–Gitbasics)•  Inaddi=ontotherepositoryitselfandtheworkingcopy,thereisathirdsec=oningitcalledthestagingarea.

•  Thestagingareaisanintermediatespacebetweentheworkingcopyandtherepositorywhereonecanpreparewhat’stobeincludedinthenextcommit.

•  Inshort,itisacommit-prepara1on-area


TheStagingArea(a.k.a.Index)


Remoterepositories

Repositoriescanbesynchronizedwithoneanother.Inthecentralizedworkflow,eachusersynchroniseshisrepositorywithacentralrepo(theremote)locatedonaserver.


LocalRepo

«Integrated»view

WorkingCopy

StagingArea

CommiUedRevisions

RemoteRepo

CommiUedRevisions

RemoteLocal


FileStatusLifecycle


Thecorrespondingcommands…

•  Addafile•  Editafile•  Stageafile•  Removeafile•  Commitafile

git add

git stage (orgit add)git rm

git commit

…arequitestraighBorward:

NB:git rm actuallydeletesthefilefromyourworkingcopy.Ifyouwanttokeepitasanuntrackedfile,usethe--cached op=on


Graphical User Interfaces 3


gitk


git-gui


Illustration of the Main Commands 4


Illustra=ons:status$ lsfoo bar$ git statusOn branch master

nothing to commit, working directory clean$

Logrev1

Logrev2

Logrev3master


Illustra=ons:untrackedfile $ lsfoo bar$ git statusOn branch master

nothing to commit, working directory clean$$ # Create a new file baz$ echo "A new file…" > baz$$ git statusOn branch masterUntracked files: (use "git add <file>…" to include in what will be committed

baz

nothing added to commit but untracked files present (use "git add" to track)$

Logrev1

Logrev2

Logrev3master


Illustra=ons:add$ git add baz

Logrev1

Logrev2

Logrev3master


Illustra=ons:add$ git add baz$ git statusOn branch masterChanges to be committed: (use "git reset HEAD <file>..." to unstage)

new file: baz

$

Logrev1

Logrev2

Logrev3

Modifsinindex

master


Illustra=ons:commit$ git add baz$ git statusOn branch masterChanges to be committed: (use "git reset HEAD <file>..." to unstage)

new file: baz

$ git commit

Logrev1

Logrev2

Logrev3

Modifsinindex

master


Illustra=ons:commit$ git add baz$ git statusOn branch masterChanges to be committed: (use "git reset HEAD <file>..." to unstage)

new file: baz

$ git commit[master 98aa7ff] Add file baz 1 file changed, 1 insertion(+) create mode 100644 baz$ git statusOn branch masternothing to commit, working directory clean$

Logrev1

Logrev2

Logrev3

Addfilebazmaster


Illustra=ons:log$ git logcommit 579001a8a6f83cb6547440ba319f7210916ece6bAuthor: David Parsons <[email protected]>Date: Sat Jan 9 17:53:11 2016 +0100

Add file baz

commit e82a7786b5ebfc1d0e62eb00ae2101a328d3f0e4Author: David Parsons <[email protected]>Date: Sat Jan 9 17:44:29 2016 +0100

Log rev3

commit f6813a3b9f081bb486975dfe5b6a426effabf61cAuthor: David Parsons <[email protected]>Date: Sat Jan 9 17:43:39 2016 +0100

Log rev2

commit f667b6e8847d20c67968c2b2d8a85fac7076251f:

Logrev1

Logrev2

Logrev3

Addfilebazmaster


Illustra=ons:log$ git log --pretty=oneline579001a8a6f83cb6547440ba319f7[…] Add file baze82a7786b5ebfc1d0e62eb00ae210[…] Log rev3f6813a3b9f081bb486975dfe5b6a4[…] Log rev2f667b6e8847d20c67968c2b2d8a85[…] Log rev1$$ git log --pretty=format:"%h - %an : %s"579001a - David Parsons : Add file baze82a778 - David Parsons : Log rev3f6813a3 - David Parsons : Log rev2f667b6e - David Parsons : Log rev1$

Logrev1

Logrev2

Logrev3

Addfilebazmaster


$ # Add content to foo$ echo "Added content" >> foo

Logrev1

Logrev2

Logrev3

Addfilebazmaster

Illustra=ons:edittrackedfile


Illustra=ons:edittrackedfile$ # Add content to foo$ echo "Added content" >> foo$

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsnotinindex

master


Illustra=ons:edittrackedfile$ # Add content to foo$ echo "Added content" >> foo$$ git statusOn branch masterChanges not staged for commit: (use "git add <file>..." to update what will be committed) (use "git checkout -- <file>..." to discard changes in working directory)

modified: foo

no changes added to commit (use "git add" and/or "git commit -a")$

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsnotinindex

master


Illustra=ons:stage$ # Mark changes in foo as ‘to be committed’$ git stage foo

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsnotinindex

master


Illustra=ons:stage$ # Mark changes in foo as ‘to be committed’$ git stage foo$$ # The exact same thing could have been done with git add foo$$ git statusOn branch masterChanges to be committed: (use "git reset HEAD <file>..." to unstage)

modified: foo

$

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

master


IndexandWorkingCopy$ # Add content to bar$ echo "Content added to bar" >> bar

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

master


$ # Add content to bar$ echo "Content added to bar" >> bar$

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

Modifsnotinindex

master

IndexandWorkingCopy


$ # Add content to bar$ echo "Content added to bar" >> bar$ git statusOn branch masterChanges to be committed: (use "git reset HEAD <file>..." to unstage)

modified: foo

Changes not staged for commit: (use "git add <file>..." to update what will be committed) (use "git checkout -- <file>..." to discard changes in working directory)

modified: bar

$

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

Modifsnotinindex

master

IndexandWorkingCopy


Illustra=ons:diff

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

Modifsnotinindex

git diff

git diff --staged

git diff HEAD

master


$ git statusOn branch masterChanges to be committed: (use "git reset HEAD <file>..." to unstage)

modified: foo


modified: bar

$

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

Modifsnotinindex

master

IndexandWorkingCopy



modified: foo


modified: bar

$ # Add more content to foo$ echo “more content” >> foo

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

Modifsnotinindex

master

IndexandWorkingCopy



modified: foo


modified: bar modified: foo

$

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

Modifsnotinindex

master

IndexandWorkingCopy


Bypassingtheindex$ # Commit working copy state of foo$ git commit foo

Logrev1

Logrev2

Logrev3

Addfilebaz

Modifsinindex

Modifsnotinindex

master


$ # Commit working copy state of foo$ git commit foo[master 5e60acc] Add content to foo 1 file changed, 2 insertions(+)$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Modifsnotinindex

Addfilebaz

master

Bypassingtheindex


$ # Commit working copy state of foo$ git commit foo[master 5e60acc] Add content to foo 1 file changed, 2 insertions(+)$$ git statusOn branch masterChanges not staged for commit: (use "git add <file>..." to update what will be committed) (use "git checkout -- <file>..." to discard changes in working directory)

modified: bar

$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Modifsnotinindex

Addfilebaz

master

Bypassingtheindex


$ # Commit working copy state of all tracked files$ git commit -a -m "Add content to bar”

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Modifsnotinindex

Addfilebaz

master

Bypassingtheindex


$ # Commit working copy state of all tracked files$ git commit -a -m "Add content to bar"[master 119dfba] Add content to bar 1 file changed, 1 insertion(+)$ git statusOn branch masternothing to commit, working directory clean$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarmaster

Bypassingtheindex


Configuringgit

# Configure your name and e-mail address (almost mandatory)# If you don’t, you’ll get:$ git commit

*** Please tell me who you are.

Run

git config --global user.email "[email protected]" git config --global user.name "Your Name"

to set your account's default identity.Omit --global to set the identity only in this repository.

# Configure your name and e-mail address$ git config --global user.name "David Parsons"$ git config --global user.email [email protected]


Configuringgit

$ # Configure the editor git will open when needed$ git config --global core.editor nano$$ # Setup a few aliases, either simple shorthands...$ git config --global alias.co checkout$ git config --global alias.ci commit$ git config --global alias.s status$$ # ... or including options$ git config --global alias.lg "log --pretty=format:\"%h - %an : %s\""$$ # You can even create new commands$ git config --global alias.unstage "reset HEAD”


INTERACTING WITH A REMOTE Scenario

5


Workinginparallel

clone clone

master

Centralrepo


masterr/o/master

Workinginparallel

master masterr/o/master

Centralrepo


Workinginparallel

master

master master

r/o/master r/o/master

Centralrepo


Workinginparallel

master

master master

push

r/o/master

Centralrepo

r/o/master


Workinginparallel

master mastermasterr/o/master

r/o/master

Centralrepo


Workinginparallel


push

r/o/master

Centralrepo


Workinginparallel


fetch

r/o/master

Centralrepo


Workinginparallel

master mastermasterr/o/master r/o/master

Centralrepo


Workinginparallel


master

r/o/master

Centralrepo


Workinginparallel


master

push

r/o/master

Centralrepo


Workinginparallel

masterr/o/master

mastermaster r/o/master

Centralrepo


Workinginparallel

masterr/o/master

mastermaster

pull

r/o/master

Centralrepo


Workinginparallel

mastermasterr/o/master master r/o/master

Centralrepo


INTERACTING WITH A REMOTE Corresponding Commands

6


Cloningarepository$ # Clone a remote repository$ # git clone <remote-repo-url> [local-name]$


Cloningarepository$ # Clone a remote repository$ # git clone <remote-repo-url> [local-name]$ git clone […]/collab.gitCloning into ‘collab'...done.$


Cloningarepository$ # Clone a remote repository$ # git clone <remote-repo-url> [local-name]$ git clone […]/collab.gitCloning into ‘collab'...done.$ cd collab # Don’t forget to cd into the local repo dir$

Addcontenttofoo

Addfilebaz

master Addcontenttobarv0.1 remotes/origin/master


$ git clone […]/collab.gitCloning into ‘collab'...done.$ cd collab # Don’t forget to cd into the local repo dir$

Otheruser’sviewpoint

Addcontenttofoo

Addfilebaz



Remotes$ # Clone a remote repository$ # git clone <remote-repo-url> [local-name]$ git clone […]/collab.gitCloning into ‘collab'...done.$ cd collab # Don’t forget to cd into the local repo dir$ git remoteorigin$ git remote –vorigin […]/collab.git (fetch)origin […]/collab.git (push)$

Addcontenttofoo

Addfilebaz



Remotetrackingbranch

Addcontenttofoo

Addfilebaz


$ # Commit stuff$ echo "This is the content of bar" > bar$

Modifsnotinindex


Remotetrackingbranch$ # Commit stuff$ echo "This is the content of bar" > bar$ git commit bar -m "Modify bar"$

Addcontenttobarremotes/origin/master

master Modifybar

Addcontenttofoo

Addfilebaz

v0.1


Push$ # Push your commits onto the remote repository$ git push


master Modifybar

Addcontenttofoo

Addfilebaz

v0.1


Push$ # Push your commits onto the remote repository$ git pushCounting objects: 3, done.Delta compression using up to 4 threads.Compressing objects: 100% (2/2), done.Writing objects: 100% (3/3), 318 bytes | 0 bytes/s, done.Total 3 (delta 0), reused 0 (delta 0)To […]/collab.git 119dfba..a8f9783 master -> master$

Addcontenttobar

master Modifybarremotes/origin/master

Addcontenttofoo

Addfilebaz

v0.1


$


Addcontenttofoo

Addfilebaz



$ # Commit stuff$ echo "This is foo’s new content" > foo$ git commit foo -m "Change foo"$


master Changefoo


Addcontenttofoo

Addfilebaz

v0.1


$ git pushTo […]/collab.git ! [rejected] master -> master (non-fast-forward)error: failed to push some refs to ‘[…]/collab.git’hint: Updates were rejected because the remote contains work that youhint: do not have locally. This is usually caused by anotherhint: repository pushing to the same ref. You may want to firsthint: integrate the remote changes (e.g., 'git pull ...') before hint: pushing again.hint: See the 'Note about fast-forwards' in 'git push --help' for details.$

Failedpush


master Changefoo

Addcontenttofoo

Addfilebaz

v0.1


$ git fetch

Fetch


master Changefoo

Addcontenttofoo

Addfilebaz

v0.1


$ git fetchFrom […]/collab.git 119dfba..a8f9783 master -> origin/master$

Addcontenttobarv0.1

Modifybar

Changefoomaster

remotes/origin/master

Fetch

Addcontenttofoo

Addfilebaz


$ git merge

Merge

Addcontenttobarv0.1

Modifybar

Changefoomaster


Addcontenttofoo

Addfilebaz

Mergingconsistsininjec=ngtheaccumulatedchangesetofr/o/masterintomaster

Amergeisembodiedbyamergecommitthathastwoparentsandthatincludesthechangesfrombothsides

Thebranchbeingmergedisuntouched


$ git mergeMerge made by the 'recursive' strategy. bar | 2 ++ 1 file changed, 2 insertions(+) create mode 100644 bar$

Changefoo

Modifybar

Mergeremote-trackingbranch'origin/master'master


Mergewithoutconflicts

Addcontenttobarv0.1

Addcontenttofoo

Addfilebaz

Whentherearenoconflictsbetweenthetwochangesets,gitmergeautoma=callytriggersthecrea=onofthemergecommit.Itwillopenyourcoreeditorwithapredefinedlogmsg


$ git push$

Mergeremote-trackingbranch'origin/master'master remotes/origin/master

Push

Changefoo

Modifybar

Addcontenttobarv0.1

Addcontenttofoo

Addfilebaz


Pull$ git pull


master Modifybar

Addcontenttofoo

Addfilebaz

v0.1


Pull$ git pull[…]$

Mergeremote-trackingbranch'origin/master'master remotes/origin/master

Changefoo

Modifybar

Addcontenttobarv0.1

Addcontenttofoo

Addfilebaz


Gitpushconfigura=on

$ # When pushing for the first time, you might get a warning message such as this one:

warning: push.default is unset; its implicit value is changing in Git 2.0 from 'matching' to 'simple'. To squelch this message and maintain the current behavior after the default changes, use:

git config --global push.default matching

To squelch this message and adopt the new behavior now, use:

git config --global push.default simple

$ # If you do, choose the new behaviour, which is safest:$ git config --global push.default simple


MANAGING CONFLICTS 7


Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

Modifybar

Changebar

$ git merge

master

Managingconflicts

r/o/master


$ git mergeAuto-merging barCONFLICT (content): Merge conflict in barAutomatic merge failed; fix conflicts and then commit the result.$

Managingconflicts

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

Modifybar

Changebarmaster

r/o/master


$ git mergeAuto-merging barCONFLICT (content): Merge conflict in barAutomatic merge failed; fix conflicts and then commit the result.$$ cat barThis is line 1This is line 2This is line 3<<<<<<< HEADThis is the fourth line=======This is line number 4>>>>>>> featureAThis is line 5This is line 6This is line 7This is line 8$

Managingconflicts

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

Modifybar

Changebarmaster

r/o/master


$ # You can edit the conflicting files directly and then stage them and commit, or you can use a merge tool$$ git mergetool

Managingconflicts

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

Modifybar

Changebarmaster

r/o/master


mergetool–p4merge


$ git config --global merge.tool meld$ git config --global mergetool.meld.cmd 'meld $LOCAL $MERGED $REMOTE'$ git config --global mergetool.meld.trustExitCode false$

Configuringamergetool


Branches 8


Whatisabranch?

branch

Eachbranchcontainsanalterna=veversionofthesamesetoffilesGitismeantforanextensiveuseofbranches«master»isthemainbranch,i.e.thatwhichischeckedoutbydefault

master


Branchtypes

branch

Gitdoesnotknowaboutbranchtypes,itistheusageyoumakeofabranchthatdeterminesits“type”

Abranchmayremainlocaltoauser’srepoorbepublished(pushed)tothecentralrepo

Commonusecasesforbranchesinclude:•  Feature•  Bugfix•  LTS•  …

master


FeatureandBugfixbranches

featureA

ThesebranchesareusefulfordevelopingafeatureorapatchwithoutmessingwiththemasterTheyareusuallymeanttobemergedbackintothemasterwhenthefeatureorpatchisreadyTheworkflowisyours(yourteam’s)todefine

master


Mergingbranches

featureA

HerewehavemergedbranchfeatureAintobranchmaster.ThismeanswehaveinjectedtheaccumulatedchangesetoffeatureAintomasterMergingalocalbranchisjustthesameasmergingaremote-trackingbranchThismergeisembodiedbyacommit(unlessitisafast-forward)thathastwoparentsandthatincludethechangesmadetobothbranches(here5changesets)BranchfeatureAisuntouched

master


Maintenancebranches

v1.1.2 Branchescanbeusedforintegra=ngbugfixesinearliermaintainedreleases(e.g.LTS)Thesebranches arenotmeant tobemerged into themaster

v1.1.0

v1.1.1

master

v1.2.0


WarningforSVNusers

•  Atany=me,yourworkingcopycontainsonlythecontentofonesinglebranch


Branches$ git branch* master$ git branch featureA

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarmasterv0.1


Branches$ git branch* master$ git branch featureA$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

featureA Addcontenttobarv0.1 master


Branches$ git branch* master$ git branch featureA$ git branch featureA* master$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz



Branches$ git branch* master$ git branch featureA$ git branch featureA* master$ git checkout featureA$ git branch* featureA master$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz


Youcanalsocreateandcheckoutanewbranchatoncewithgit checkout –b newBranch


Branches$ # Commit stuff in branch featureA$ echo “Blabla” >> foo$ git commit foo -m “Modify foo”

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz


Modifsnotinindex


Branches$ # Commit stuff in branch featureA$ echo “Blabla” >> foo$ git commit foo -m “Modify foo”$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Add[…]barv0.1

ModifyfoofeatureA

master


Branches$ # Checkout branch master and commit stuff in it$ git checkout master$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Add[…]barv0.1

ModifyfoofeatureA

master


Branches

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

ModifyfoofeatureA

$ # Checkout branch master and commit stuff in it$ git checkout master$ echo “Blabla” >> bar$ git commit foo -m “Modify bar”$

Modifybarmaster


Mergingbranches

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

ModifyfoofeatureA

Modifybarmaster

$ git merge featureA


Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

Modifybar

ModifyfoofeatureA

Mergebranch‘featureA’master

Mergingalocalbranchisjustthesameasmergingaremote-trackingbranch

$ git merge featureA$

Mergingbranches


Tags 9


Tags

$ # Create an annotated tag named "v0.1"$ git tag –a v0.1 –m “version 0.1”

$ # List tags$ git tagv0.1$

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1 master

Atagistypicallyusedtomarkareleasepoint.Thereare2typesoftags:•  Lightweight(justareferencetoaspecificcommit)•  Annotated(fullobject,containsaddi=onalinfo,canbesigned)


Tags

Tagshavetobepushedandfetchedmanuallygit push origin <tagname>orgit push origin –tags

Git fetch origin --tags


Tree-ish ? 10


Tree-ish:aconceptyoushouldknowof

Acommitcanbeiden=fiedinmul=pleways,e.g.:•  ItsSHA1(possiblyabbreviated)•  Abranchname•  Atag•  Areference(e.g.HEAD,…)•  Anindirectreference:HEAD^,HEAD~,master~3,…•  …


Indirectreferences

Acommitcanbeiden=fiedindirectlyusingabasecommitfollowedbyanycombina=onofthe^and~operators:•  C^n:breadthfirstoperator– getsthenthparentofcommitC•  C~n:depthfirstoperator– getstheancestorofcommitC,n

genera=onsback,alwaysfavouringthefirstparent•  N==1bydefault

•  D==B^1==B^==B~1==B~•  D==A~2==A~1~1==A^^…•  C==A^2

A

B

D

C


Merge or Rebase ? 11


Rebase$ git rebase

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

Modifybar

Changebarmaster



Rebase$ git rebase$

Logrev1

Logrev2

Logrev3

Addcontenttofoo

Addfilebaz

Addcontenttobarv0.1

Changebar

Changebarmaster remotes/origin/master

Modifybar

ThiswasyourHEADjustbeforetherebase

Thisisabrandnewcommit


•  Rebasingbasicallymeansre-wri=ngthehistoryofwhathappened.Thisisaverypowerfulfeature,inpar=cularintheinterac=vemode(rebase -i).Butasalways,greatpowercomeswithgreatresponsibility

DONOTREBASECOMMITSTHATEXISTOUTSIDEYOURREPOSITORY

Rebaseonlylocalcommits


Whichonewouldyouprefer?

Merge Rebase

Mergeorrebase?


Mergeorrebase?

Ormaybethismixedone?

Merge RebaseMixed


To go further… 12


•  Addi=onalcommandsorop=ons•  commit --amend•  stash / stash pop•  rebase –i•  add –p•  cherry-pick•  bisect•  revert•  Andsomanymore…

•  git-awtude.fr

Togofurther…

LIEULOCALISATION

www.inria.frAntenneINRIALyonlaDoua

www.inria.fr

Thank you

INTRODUCTION TO GIT · DAVID PARSONS - INTRODUCTION TO GIT 12 The Staging Area (a.k.a Index) •...

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