This cheat sheet tells how to use Git , a very popular version control system. Git is used in many open-source projects. We will cover the following
- How to install and set up Git on a Windows computer.
- Basic commands for working with files and directories on the UNIX/Linux command line.
- Basic Git commands for making and working with a local repository.
- Working with a remote repository in a team on both GitHub and BitBucket.
- Resources you can consult if you want more detailed information.
To install Git, first download it from http://git-scm.com/download/win. The download will start automatically. Once the file has finished downloading on your computer, run it. I recommend that you let the installer create a desktop shortcut to the Git Bash shell for you. This way, the Git command line environment will start for you, when you want to work with Git. I also recommend that you create a local folder to hold your local repositories that you will use to house the changes you work on when you work with teams, and any repositories that you work with on your own. I also recommend that you point the shortcut to the local folder where you keep your repositories. To do that, find the shortcut on your desktop and press ALT+ENTER. Tab into the ""Start in"" box and type the path to the local repository.
Basic Unix Commands For Directories and Files
Below are some basic commands that will allow you to work with the command line, since when you run Git, you will be using a UNIX command line.
Print The Current Directory
List the Contents of the Current Directory
List files and directories, one per line.
Change To a Directory
Note: The absolute path to a directory starts at the root. The relative path of a directory starts at the current directoory.
Move Up Toward The Root One Level
Create a Directory
Workflow In Brief For Contributing to a GitHub or BitBucket project
This is a list of the activities you will go through as you work on a project on Github or BitBucket.
- Set up Git on your local computer.
- Sign up for an account at http://www.github.com/ or http://www.bitbucket.com/.
- Log onto Github or BitBucket.
- Find the repository you want to work with.
- Click Fork to get your own copy of the repository under your account.
- Copy the URL for your new repository to the clipboard using the control for that purpose.
- Open Git on your local computer.
- Clone your new repository to your local machine using the URL you copied to the clipboard. Tip: On BitBucket, the entire Git command will be on the clipboard. In GitHub, the URL only will be in the clipboard. With the Git Bash command line open, you can get the contents of the clipboard onto the command line by pressing ALT+SPACE, E, then P. You can then use arrow keys, HOME, END, BACKSPACE, and DELETE to edit the command line.
- Create and work on a branch.
- Push the branch back up to your GitHub repository.
- Sync your remote repository to the team repository, if necessary.
- Create a pull request on GitHub or BitBucket for the project owner to review.
- Continue to work on the current branch or make other branches to work on.
- Delete local branch or branches when finished.
Below are more details about the tasks you will perform to make changes to a repository. We pick up after you have decided on a project to which you want to contribute and have forked the repository. Keep in mind that there are other variations on the commands I show here that can make your job easier by combining steps, but I present things this way, so that you see every step in the process so that you know exactly how it works. I trust that if you want to shorten the process once you know how it works, that you can use the
git help command or consult "Pro Git" to explore making this process more efficient.
Clone Your Forked repository
Use the following command to put a local copy of your repository onto your computer.
git clone <repository>
Checking The Status of Your Local Repository
Any time you want to check the status of your local repository, use this command.
Tipp: run the
status command after each other command to get a feel for the kinds of information Git keeps track of.
Create A Branch
Create a branch to keep yourself from accidentally altering the original project. Git always creates a branch called master when you clone the repository. Note: If a project has more than one branch, you can do the same for that branch. You just have to know the name of the branch you want to work with. In this example, we assume that you want to change the branch called "master."
git branch <branch>
Once you have created the new branch, you have to switch to it, so you can work on the project branch. Git does not switch to a branch when you use the branch command unless you use a command argument. To switch to the new branch, run this command.
git checkout <branch>
Git is now pointing to the new branch. Any changes you make will go into this branch.
Change a File
To keep it simple, we’re going to say that your going to either change one file, or add one to your new branch. So we pick up after you’ve changed or added a file. Once you have saved the file, you would go to the Git command line. At this point, your change is not in the new branch.
git status to see what’s going on.
Adding Your Change To The New Branch
git add <file>
git status again to see what just happened.
Note: if you need to make another change to your file, you need to run
git add <file> again.
Add The File To The Branch of the Local Repository
Your file is not yet in your repository. To do that, run this command.
git commit -m "Message"
"Message" is a description of the change, so that you remember what happened.
Once again, run
git status to see what happened.
Reviewing What happened
git status shows the state of your local repository. You can also run
git status --short to get more simplified output.
git diff gives you detailed information about what changed.
git diff --staged compares the staged files to your last commit. The term "staged" means files you have used the
git add command on, but which you have not put into your local repository by running
git commit -m"message".
Print A History Of Commits
git log --oneline --decorate --graph --all
This shows you the commits you have made as you’ve been working on a local repository.
Merge Your Branch Into Your Local Repository
You would do this when you are satisfied with the changes you want to make. To get your new branch into your local repository, use the following two commands.
git checkout master git merge <branch>
The first command makes Git point to the branch called master, so that you can put your changes into the repository.
The second command puts the new changes into your repository.
Deleting A Branch
For whatever reason, you might want to delete a branch. You may decide that you don’t want to merge the branch into your project afterall, or you might simply be done working on that branch and want to clean up. To delete a branch, type this command.
git branch -d <branch>
Put Your Changes Up On GitHub or BitBucket
Now that you’ve made changes to your local repository, you will want to put those changes on your repository on GitHub or BitBucket. If you are working alone, chances are that you would want to simply put your changes up on the server and move onto the next changes. This guide assumes that you are working on a team, however, and that you want your repository to stay in sync with the one you forked it from. This section tells how to get your remote repository in sync with the original.
Syncing Your Remote Repository To The Original
A remote is a repository on a server. In otherwords, not on your computer. The one on your computer is local. When you first clone or create the local repository, Git gives the remote repository the name "origin by default."
List Remote Repositories
git remote -v
At this point, git should only show your forked repository, and its name should be "origin."
Specify The Original Repository
Note: we’ll name the new remote repository "upstream," just to emphasize that origin, the one we created to hold the changes gets the new material from the repository we cloned.
git remote add upstream <url>
git remote add command by editing the command line.
List Remote Repositories Again
Now you can verify the new upstream repository you’ve specified.
git remote -v
This time you see the names of both the repository you forked and the upstream repository.
From this point forward, you no longer have to perform this step.
Sync Your Forked Repository With The Upstream Repository
It’s a good idea to sync your forked repository with the upstream one before you start working on new changes, in case you went to bed and someone in another part of the world worked on it. So before you start making changes, use the below commands.
git fetch upstream git fetch origin
Now, to start working on your changes locally, check out your fork’s local master branch.
git checkout master
Merge the changes from upstream/master into your local master branch. This brings your fork’s master branch into sync with the upstream repository, without losing your local changes.
git merge upstream/master
Push Your Changes Up To The Server
When you are done making changes, push your local changes up to your git repository on the server by typing the below command.
git push origin
When you are done working on local changes, and you want to let the team know that you have made changes and would like them to put them into the team repository, you would go to GitHub or BitBucket and create the pull request.