Git primer

gitr’ done!
A brief introduction to
distributed version control with git
Oscar Nierstrasz — University of Bern — scg.unibe.ch

Why git?

Bob
Carol

Bob
Carol
Alice
Ted

Bob
Carol
Alice
Ted
A recipe for disaster!

The git object model

A “blob” is content under version control (a file)
blob

You can have trees of blobs
(directories of files)
tree
blob
tree
blob
blob

A “commit” is a tree of blobs
(a set of changes)
commit
tree
blob
tree
blob
blob

Most commits modify (or merge) earlier commits
commit
commit
tree
tree
blob
blob
tree
blob
blob

You can “tag” an interesting commit
tag
commit
commit
tree
tree
blob
blob
tree
blob
blob

A graph of commits may belong to a branch
branch
tag
commit
commit
tree
tree
blob
blob
tree
blob
blob

HEAD
“HEAD “is the current branch
branch
tag
commit
commit
tree
tree
blob
blob
tree
blob
blob

HEAD
branch
commit
commit
Let’s focus on commits and branches

Basic git

Create a git repo
HEAD
mkdir repo
cd repo
git init
master
C0

Tell git to “stage” changes
HEAD
git add …
master
C0

HEAD
Commit your changes
master
C1
git commit …
C0

Collaborating

John
Jane
Public repo
Local repo
Local repo
master
C1
C0

John
Jane
Public repo
Local repo
Local repo
git clone …
master
master
master
C1
C1
C1
C0
C0
C0
git clone …

John
Jane
Public repo
Local repo
Local repo
master
master
master
C1
C2
C3
C0
C1
C1
C0
C0
git add …
git commit …
git add …
git commit …

John
Jane
Public repo
Local repo
Local repo
git pull
master
master
master
C1
C2
C3
C0
C1
C1
C0
C0
(nothing new to pull)

John
Jane
Public repo
Local repo
Local repo
git push
master
master
master
C2
C2
C3
C1
C1
C1
C0
C0
C0

John
Jane
Public repo
Local repo
Local repo
git fetch
master
master
master
C2
C2
C3
C2
C1
C1
C1
C0
C0
C0

John
Jane
Public repo
Local repo
Local repo
git merge
master
master
master
C2
C4
C2
C3
C2
C1
C1
C1
C0
C0
C0
NB:git pull = fetch + merge

John
Jane
Public repo
Local repo
Local repo
git push
master
master
master
C4
C4
C2
C3
C2
C3
C2
C1
C1
C1
C0
C0
C0

John
Jane
Public repo
Local repo
Local repo
git pull
master
master
master
C4
C4
C4
C3
C3
C2
C2
C3
C2
C1
C1
C1
C0
C0
C0

Branching and merging

“origin” refers to the remote repo
HEAD
master
origin/master
C1
C0

HEAD
master
…
git commit …
origin/master
C2
C1
C0

git branch tryout
HEAD
tryout
master
origin/master
C2
C1
C0

git checkout tryout
HEAD
tryout
master
origin/master
C2
C1
NB:git checkout –b … = branch + checkout
C0

HEAD
tryout
master
git commit …
C3
origin/master
C2
C1
C0

HEAD
tryout
master
C3
C5
origin/master
C2
C1
origin/idea
C4
C6
C0
git fetch origin

git merge origin/master origin/idea
HEAD
tryout
C7
master
C3
origin/master
C5
C2
C1
C4
C6
C0
origin/idea

git checkout master
tryout
HEAD
C7
master
C3
origin/master
C5
C2
C1
C4
C6
C0
origin/idea

git merge
HEAD
tryout
master
C7
C8
C3
origin/master
C5
C2
C1
C4
C6
C0
origin/idea

git push
HEAD
tryout
master
C7
origin/master
C8
C3
C5
C2
C1
C4
C6
C0
origin/idea

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.html
http://git-scm.com/
https://github.com/
http://www.slideshare.net/chacon/getting-git
http://oreilly.com/

License
Attribution-ShareAlike 2.5
You 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/

Git primer

by Oscar Nierstrasz

Accessibility

Categories

Upload Details

Usage Rights

1 Embed 1

Statistics

Git primer Presentation Transcript