Git is a distributed version control system.
“Distributed” = everyone has and entire copy/history of the repository, not just the current copy like in svn. All working copies are a full copy of the repository.
Because of that, in Git most operatins are local; hence, it’s fast (whilst svn is all remote and slow).
It’s used for Linux kernel, Xorg X Server, Android, VLC and others…
Single developer mode
Tell git who we are:
git config –global user.name “Luca”
git config –global user.email “luca@somemail.com”
Use colors:
git config –global color.diff auto
git config –global color.status auto
git config –global color.branch auto
Settings are saved in %USER_HOME%/.gitconfig
Create a project
mkdir SomeProject
cd SomeProject
Set up the repository for our project
(we are in SomeProject folder)
git init
> Initialized empty Git repository in %USER_HOME/luca/SomeProject/.git/
(Yes, the repo has to be inside the project folder)
Get info on the repo:
git status
git log
Commit changes is a 2-step process
Why? Because we my want to have files that are only for personal use but have no bearing on the project itself. (example: notes and sketches)
Git commits only changes to files that we staged for commit.
1. Add a file to the repository and stage it for commit
git add nameoffile
2. Commit changes
git commit -m ‘some message’
Each commit gets a SHA1 hash number for data integrity.
Or you can perform steps 1. and 2. in once:
git commit -a
Empty the staging area:
git reset
Empty the staging area and revert the changes to the files:
git reset –hard
Create a remote repo
A remote repo can be an external drive or a remote server accessed through ssh.
cd G: // an external drive, for instance
md Backup
cd Backup
git init –bare // this reates a remote repo
Add a remote repo to our project to push to
git remote add remote_name path_or_url_to_the_remote
If remote_name == “origin”, it will be the default remote server git pushes to.
Push changes to a remote repo
If the remote is empty, you also create the master branch
git push remote_name master
Following pushes:
git push remote_name
Multiple developer mode
The remote repo had better be a server!
Protocols to access the server: WebDav, git://, SSH
Create a remote SSH repository
ssh luca@sshservername
> enter password
mkdir export/git
cd export/git
mkdir ProjectServer
cd ProjectServer
git init –bare –shared
exit // exit the ssh session
Add the remote SSH server to push to
(we are in SomeProject folder)
git remote add remote_server_name luca@sshservername:/export/git/ProjectServer
If server_name == “origin”, it will be the default remote server git pushes to.
Push to the SSH remote
git push origin master
> enter ssh password
Before doing push, remember to do fetch+rebase!
Fetching changes is a 2 step process
git fetch remote_name // gets the changes
git rebase remote_name/branch_name // applies changes to our local repo
> enter ssh password
Remove a remote
git remote rm remote_name
Github
Add a remote github repo
git remote add origin git@github.com:username/repo_name.git // github creates ssh repos
Clone: creates a local repo cloning the contents of the remote repo
git clone git@github.com:username/repo_name.git
More on Rebase
1. Reverts your local repo changes back to where the local was the same as the remote.
2. Applies changes from the remote.
3. Adds your changes back on top.
Pull
1. Applies the remote’s changes on top of our local’s.
