Post on 12-May-2015
description
git r’ done!
A brief introduction todistributed version control with git
Oscar Nierstrasz — University of Bern — scg.unibe.ch
Why git?
Bob
BobCarol
BobCarol
TedAlice
BobCarol
TedAlice
A recipe for disaster!
The git object model
blob
A “blob” is content under version control (a file)
blob
blob
tree
tree
blob
You can have trees of blobs(directories of files)
blob
commit
blob
tree
tree
blob
A “commit” is a tree of blobs(a set of changes)
commit
blob
tree
blob
commit
blob
tree
tree
blob
Most commits modify (or merge) earlier commits
commit
blob
tree
tag
blob
commit
blob
tree
tree
blob
You can “tag” an interesting commit
commit
blob
tree
tag
branch
blob
commit
blob
tree
tree
blob
A graph of commits may belong to a branch
commit
blob
tree
tag
HEAD
branch
blob
commit
blob
tree
tree
blob
“HEAD “is the current branch
commit
HEAD
branch
commit
Let’s focus on commits and branches
Basic git
mkdir repocd repogit init C0
HEAD
master
Create a git repo
C0
HEAD
master git add …
Tell git to “stage” changes
C1
HEAD
master
git commit …
Commit your changes
C0
Collaborating
Public repo
C1
master
C0
Local repo
John Jane
Local repo
Public repo
C1
master
C0
Local repo
John Jane
Local repo
git clone …
git clone …
C1
master
C0
C1
master
C0
Public repo
C1
master
C0
Local repo
John Jane
Local repo
git add …git commit …
C2
master
C1
C3
master
C1
C0C0
git add …git commit …
Public repo
C1
master
C0
Local repo
John Jane
Local repo
C2
master
C1
C3
master
C1
C0C0
git pull
(nothing new to pull)
Public repoLocal repo
John Jane
Local repo
C2
master
C1
C3
master
C1
C0C0
git push
C2
master
C1
C0
Public repoLocal repo
John Jane
Local repo
C2
master
C1
C3
master
C1
C0C0
git fetch
C2
master
C1
C0
C2
Public repoLocal repo
John Jane
Local repo
C2
master
C1 C3
master
C1
C0
C0
C2
master
C1
C0
C2
C4
git merge
NB: git pull = fetch + merge
Public repoLocal repo
John Jane
Local repo
C2
master
C1 C3
master
C1
C0
C0
C2
C4
git push
C3
master
C1
C0
C2
C4
Public repoLocal repo
John Jane
Local repo
C3
master
C1
C0
C2
C4
git pull
C3
master
C1
C0
C2
C4
C3
master
C1
C0
C2
C4
Branching and merging
C1
master
origin/master
C0
HEAD
“origin” refers to the remote repo
C1
master
origin/master
C0
HEAD
C2…git commit …
C1
master
origin/master
C0
HEAD
C2
git branch tryout
tryout
C1
master
origin/master
C0
C2
tryout
git checkout tryout
NB: git checkout –b … = branch + checkout
HEAD
C1
master
origin/master
C0
C2
tryout
git commit …
HEAD
C3
C1
master
origin/master
C0
C2
tryout
git fetch origin
HEAD
C3
C4
C5
C6 origin/idea
C1
master
origin/master
C0
C2
tryout
git merge origin/master origin/idea
HEAD
C3
C4
C5
C6
origin/idea
C7
C1
master
origin/master
C0
C2
tryout
git checkout master
HEAD
C3
C4
C5
C6
origin/idea
C7
C1
master
origin/master
C0
C2
tryout
git merge
HEAD
C3
C4
C5
C6
origin/idea
C7C8
C1
master
origin/master
C0
C2
tryout
git push
HEAD
C3
C4
C5
C6
origin/idea
C7C8
More to git
More to git …
• Merging and mergetool• Squashing commits when merging• Resolving conflicts• User authentication with ssh• gitx and other graphical tools• git configure — remembering your name• git remote — multiple remote repos• github — an open source public repo• …
Resources
http://book.git-scm.com/index.htmlhttp://git-scm.com/
https://github.com/
http://www.slideshare.net/chacon/getting-git http://oreilly.com/
License
Attribution-ShareAlike 2.5You are free:• to copy, distribute, display, and perform the work• to make derivative works• to make commercial use of the work
Under the following conditions:
Attribution. You must attribute the work in the manner specified by the author or licensor.
Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one.
• For any reuse or distribution, you must make clear to others the license terms of this work.• Any of these conditions can be waived if you get permission from the copyright holder.
Your fair use and other rights are in no way affected by the above.
http://creativecommons.org/licenses/by-sa/2.5/