Git

git is a distributed versioning & revisioning system. It can be used locally and remotely.

git automatically tracks all files that were changed and has the ability to synchronize the files to a remote server.

In order to use git, you need to have git installed on your computer, which is most likely the case if you're on a Mac or a Linux system. For all other cases, you can get git here: git-scm.com.

This page shows some common commands, but remember that most modern IDEs support versioning systems like git with an additional graphical user interface (in case of Xcode there's a code-timeline and built-in file merging capability).

Setup

With other revisioning systems, it can be quite a hassle to create an initial setup for a folder, with git this is really easy. Just open up your shell, change the directory to the directory you wish to use git and type:

cd myProjectPath
git init

To add a remote git server, type:

git remote add origin ssh://myserver.com

For example, you can use github.com to host your open source projects, or bitBucket.org. You will find an excessive online help on how to setup a remote server on github: How-to-Setup github. Basically, you only need a private/public ssh key and a valid user account.

But remember, you can use git only on your local computer as well, it is not required to have an online server!

Usage

to get the status of your local git repository, query:

git status

to add files you type:

git add myfile.ext

or to add all:

git add *

If you changed something and would like to store these changes as a version, you can "commit" your update:

git commit -a -m "comment about change"

At this point, your commit is only local! You can commit as few or as many changes as you like. But at the end of the day, you should push your changes to the server:

git push origin master

If you are interested in getting the changes from the server to your local machine, type:

git pull

That's all for the beginning!
Easy, isn't it?

Advantages

Setting up a versioning repository has many advantages, these are just a few:

With a local git repository, you always have:

• multiple backups
• the possibility to revert to any file state at any time
• no fear to overwrite anything
• merge changes

With an (additional) online repository, you can:

• work with multiple people on the same project
• work from multiple computers on the same project
• merge changes
• branch other projects (make your own copy)
• send pull requests to the master branch: if you changed something and would like to contribute to the original project, you can easily request these updates

So: forget CVS and SVN, with GIT there's really no excuse to not use a versioning systems anymore. There is also bazaar, which claims to be even easier than GIT, but isn't as widely adoptet.

Links

• git-scm - Official Project Page
• gitref.org - Git Reference
• gir.or.cz Crash Course about git
• github.com
• bitBucket.org