All of these steps are just copy & paste from try.github.io (big thanks to codeschool.com for putting them all together), plus some addional tips I found from other resources.

1.1 Got 15 minutes and want to learn Git?

Git allows groups of people to work on the same documents (often code) at the same time, and without stepping on each other's toes. It's a distributed version control system.

Our terminal prompt below is currently in a directory we decided to name "octobox". To initialize a Git repository here, type the following command:

git init

Repository - A directory where Git has been initialized to start version controlling your files.

1.2 Checking the Status

Good job! As Git just told us, our "octobox" directory now has an empty repository in /.git/. The repository is a hidden directory where Git operates.

To save your progress as you go through this tutorial -- and earn a badge when you successfully complete it -- head over to create a free Code School account. We'll wait for you here.

Next up, let's type the git status command to see what the current state of our project is:

git status

The .git directory - The .git directory it's usually hidden. If you open it you'll notice it has all sorts of directories and files inside it. You'll rarely ever need to do anything inside here but it's the guts of Git, where all the magic happens.

1.3 Adding & Committing

I created a file called octocat.txt in the octobox repository for you (as you can see in the browser below).

You should run the git status command again to see how the repository status has changed:

git status

It's healthy to run git status often. Sometimes things change and you don't notice it.

1.4 Adding Changes

Good, it looks like our Git repository is working properly. Notice how Git says octocat.txt is "untracked"? That means Git sees that octocat.txt is a new file.

To tell Git to start tracking changes made to octocat.txt, we first need to add it to the staging area by using git add.

git add octocat.txt

staged - Files are ready to be committed.

unstaged - Files with changes that have not been prepared to be committed.

untracked - Files aren't tracked by Git yet. This usually indicates a newly created file.

deleted - File has been deleted and is waiting to be removed from Git.

1.5 Checking for Changes

Good job! Git is now tracking our octocat.txt file. Let's run git status again to see where we stand:

git status

git add -A - (default behavior for git add). This will add all new, changed, deleted and hidden files from the current directory, subdirectories and parent directories as well (if there are some).

git add -A . - This will add all new, changed, deleted and hidden files from the current directory only.

git add -A <dir> - This will add all new, changed, deleted and hidden files from the specified directory only.

git add -u - This is similar with git add -A, but will only add updated and deleted files to the staging area.

git add . - This is the same as git add -A .

git reset <filename> - You can use this command to remove a file or multiple files from the staging area.

git reset - You can use this command to remove all files from the staging area.

1.6 Committing

Notice how Git says changes to be committed? The files listed here are in the Staging Area, and they are not in our repository yet. We could add or remove files from the stage before we store them in the repository.

To store our staged changes we run the commit command with a message describing what we've changed. Let's do that now by typing:

git commit -m "Add cute octocat story"

Staging Area - A place where we can group files together before we "commit" them to Git.

Commit - A "commit" is a snapshot of our repository. This way if we ever need to look back at the changes we've made (or if someone else does), we will see a nice timeline of all changes.

Multi-line commit message - For a multi-line commit message, you only need to run git commit without -m. This will open a VI text editor in your terminal. Write your multi-line message here (create a new line break by hitting enter) and then press esc and write :wq and hit enter.

Change the commit message for your latest commit (w/o creating a new commit) - if you ever need to do that, then you can run git commit --amend -m "YOUR NEW MESSAGE HERE". CAREFUL - this will update the git history (it changes the history log's unique hash). It is recommended to run this commend, only if you're the only one who have seen the history (working on a temporary branch for example). If you'll change the history of any other developers, then this can cause issues with their repositories.

Add a file to the latest commit (w/o creating a new commit) - if you ever need to do that then, first of all, you need to make sure that your file was added to the staging area (via git add <file>), then you need to run git commit --amend. This will open up the Vim editor where you can update the latest commit's message if you need to. After that just press esc, write :wq and hit enter. To check if your file was successfully added to the latest commit, you can run git log --stat. CAREFUL - this will update the git history as well.

Revert some existing commits - run git revert <commit> to revert a previously created commit. As a result, if you check git log, then you'll notice that the commit we tried to revert is still there untouched, and now there's a new commit that says: Revert "YOUR REVERTED COMMIT'S MESSAGE".

1.7 Adding All Changes

Great! You also can use wildcards if you want to add many files of the same type. Notice that I've added a bunch of .txt files into your directory below.

I put some in a directory named "octofamily" and some others ended up in the root of our "octobox" directory. Luckily, we can add all the new files using a wildcard with git add. Don't forget the quotes!

git add '*.txt'

We need quotes so that Git will receive the wildcard before our shell can interfere with it. Without quotes our shell will only execute the wildcard search within the current directory. Git will receive the list of files the shell found instead of the wildcard and it will not be able to add the files inside of the octofamily directory.

Some more examples:

Add a list of files - git add <list of files>

Add all files - git add -A or git add --all

Add all txt files in current directory - git add *.txt

Add all txt files in docs directory - git add docs/*.txt

Add all files in docs directory - git add docs/

Add all txt files in the whole project - git add '*.txt'

1.8 Committing All Changes

Okay, you've added all the text files to the staging area. Feel free to run git status to see what you're about to commit.

If it looks good, go ahead and run:

git commit -m 'Add all the octocat txt files'

When using wildcards you want to be extra careful when doing commits. Make sure to check what files and folders are staged by using git status before you do the actual commit. This way you can be sure you're committing only the things you want.

1.9 History

So we've made a few commits. Now let's browse them to see what we changed.

Fortunately for us, there's git log. Think of Git's log as a journal that remembers all the changes we've committed so far, in the order we committed them. Try running it now:

git log

Use git log --summary to see more information for each commit. You can see where new files were added for the first time or where files were deleted. It's a good overview of what's going on in the project.

Use git log --oneline to see a very compact version of git log

1.10 Remote Repositories

Great job! We've gone ahead and created a new empty GitHub repository for you to use with Try Git at https://github.com/try-git/try_git.git. To push our local repo to the GitHub server we'll need to add a remote repository.

This command takes a remote name and a repository URL, which in your case is https://github.com/try-git/try_git.git.

Go ahead and run git remote add with the options below:

git remote add origin https://github.com/try-git/try_git.git

Git doesn't care what you name your remotes, but it's typical to name your main one origin. It's also a good idea for your main repository to be on a remote server like GitHub in case your machine is lost at sea during a transatlantic boat cruise or crushed by three monkey statues during an earthquake.

1.11 Pushing Remotely

The push command tells Git where to put our commits when we're ready, and boy we're ready. So let's push our local changes to our origin repo (on GitHub).

The name of our remote is origin and the default local branch name is master. The -u tells Git to remember the parameters, so that next time we can simply run git push and Git will know what to do. Go ahead and push it!

git push -u origin master

When you start to get the hang of git you can do some really cool things with hooks when you push. For example, you can upload directly to a webserver whenever you push to your master remote instead of having to upload your site with an ftp client. Check out Customizing Git - Git Hooks for more information.

1.12 Pulling Remotely

Let's pretend some time has passed. We've invited other people to our GitHub project who have pulled your changes, made their own commits, and pushed them.

We can check for changes on our GitHub repository and pull down any new changes by running:

git pull origin master

Sometimes when you go to pull you may have changes you don't want to commit just yet. One option you have, other than commiting, is to stash the changes. Use the command 'git stash' to stash your changes, and 'git stash apply' to re-apply your changes after your pull.

1.13 Differences

Uh oh, looks like there have been some additions and changes to the octocat family. Let's take a look at what is different from our last commit by using the git diff command.

In this case we want the diff of our most recent commit, which we can refer to using the HEAD pointer.

git diff HEAD

The HEAD is a pointer that holds your position within all your different commits. By default HEAD points to your most recent commit, so it can be used as a quick way to reference that commit without having to look up the SHA.

run git diff HEAD~ or git diff @~ to see the difference between last but one commit and last commit (plus current state, if any)

Use git show HEAD~1 to show the last-but-one commit, and git show HEAD~2, etc. for older commits.

1.14 Staged Differences

Another great use for diff is looking at changes within files that have already been staged. Remember, staged files are files we have told git that are ready to be committed.

Let's use git add to stage octofamily/octodog.txt, which I just added to the family for you.

git add octofamily/octodog.txt

1.15 Staged Differences (cont'd)

Good, now go ahead and run git diff with the --staged option to see the changes you just staged. You should see that octodog.txt was created.

git diff --staged

1.16 Resetting the Stage

So now that octodog is part of the family, octocat is all depressed. Since we love octocat more than octodog, we'll turn his frown around by removing octodog.txt.

You can unstage files by using the git reset command. Go ahead and remove octofamily/octodog.txt.

git reset octofamily/octodog.txt

You want to try to keep related changes together in separate commits. Using 'git diff' gives you a good overview of changes you have made and lets you add files or directories one at a time and commit them separately.

1.17 Undo

git reset did a great job of unstaging octodog.txt, but you'll notice that he's still there. He's just not staged anymore. It would be great if we could go back to how things were before octodog came around and ruined the party.

Files can be changed back to how they were at the last commit by using the command: git checkout -- <file>. Go ahead and get rid of all the changes since the last commit for octocat.txt

git checkout -- octocat.txt

So you may be wondering, why do I have to use this '--' thing? git checkout seems to work fine without it. It's simply promising the command line that there are no more options after the '--'. This way if you happen to have a branch named octocat.txt, it will still revert the file, instead of switching to the branch of the same name.

1.18 Branching Out

When developers are working on a feature or bug they'll often create a copy (aka. branch) of their code they can make separate commits to. Then when they're done they can merge this branch back into their main master branch.

We want to remove all these pesky octocats, so let's create a branch called clean_up, where we'll do all the work:

git branch clean_up

Branches are what naturally happens when you want to work on multiple features at the same time. You wouldn't want to end up with a master branch which has Feature A half done and Feature B half done. Rather you'd separate the code base into two "snapshots" (branches) and work on and commit to them separately. As soon as one was ready, you might merge this branch back into the master branch and push it to the remote server.

git branch - list all local branches

git branch -a - list all local and remote branches

1.19 Switching Branches

Great! Now if you type git branch you'll see two local branches: a main branch named master and your new branch named clean_up.

You can switch branches using the git checkout command. Try it now to switch to the clean_up branch:

git checkout clean_up

You can use git checkout -b new_branch to checkout and create a branch at the same time. This is the same thing as doing:

git branch new_branch
git checkout new_branch

1.20 Removing All The Things

Ok, so you're in the clean_up branch. You can finally remove all those pesky octocats by using the git rm command which will not only remove the actual files from disk, but will also stage the removal of the files for us.

You're going to want to use a wildcard again to get all the octocats in one sweep, go ahead and run:

git rm '*.txt'

Removing one file is great and all, but what if you want to remove an entire folder? You can use the recursive option on git rm: git rm -r folder_of_cats This will recursively remove all folders and files from the given directory.

1.21 Commiting Branch Changes

Now that you've removed all the cats you'll need to commit your changes.

Feel free to run git status to check the changes you're about to commit.

git commit -m "Remove all the cats"

If you happen to delete a file without using 'git rm' you'll find that you still have to 'git rm' the deleted files from the working tree. You can save this step by using the '-a' option on 'git commit', which auto removes deleted files with the commit.

git commit -am "Delete stuff"

1.22 Switching Back to master

Great, you're almost finished with the cat... er the bug fix, you just need to switch back to the master branch so you can copy (or merge) your changes from the clean_up branch back into the master branch.

Go ahead and checkout the master branch:

git checkout master

If you're hosting your repo on GitHub, you can do something called a pull request. A pull request allows the boss of the project to look through your changes and make comments before deciding to merge in the change. It's a really great feature that is used all the time for remote workers and open-source projects. Check out the pull request help page for more information.

1.23 Preparing to Merge

Alrighty, the moment has come when you have to merge your changes from the clean_up branch into the master branch. Take a deep breath, it's not that scary.

We're already on the master branch, so we just need to tell Git to merge the clean_up branch into it:

git merge clean_up

Merge Conflicts can occur when changes are made to a file at the same time. A lot of people get really scared when a conflict happens, but fear not! They aren't that scary, you just need to decide which code to keep.

Merge conflicts are beyond the scope of this course, but if you're interested in reading more, take a look the section of the Pro Git book on how conflicts are presented.

A simple way to fix conflicts is to manually edit the file that has conflicts and decide what changes to keep. After you updated the file, run git add <file> to add the file to the staging area and then run git commit.

1.24 Keeping Things Clean

Congratulations! You just accomplished your first successful bugfix and merge. All that's left to do is clean up after yourself. Since you're done with the clean_up branch you don't need it anymore.

You can use git branch -d to delete a branch. Go ahead and delete the clean_up branch now:

git branch -d clean_up

What if you have been working on a feature branch and you decide you really don't want this feature anymore? You might decide to delete the branch since you're scrapping the idea. You'll notice that git branch -d bad_feature doesn't work. This is because -d won't let you delete something that hasn't been merged.

You can either add the --force (-f) option or use -D which combines -d -f together into one command.

Delete a remote branch - git branch -d clean_up will only remove the branch locally, but if it happened that you pushed that branch to the remote repository as well, then you need to run git push origin --delete clean_up to remove that branch from the remote repository.

1.25 The Final Push

Here we are, at the last step. I'm proud that you've made it this far, and it's been great learning Git with you. All that's left for you to do now is to push everything you've been working on to your remote repository, and you're done!

git push

We only scratched the surface of Git in this course. There is so much more you can do with it. Check out the Git documentation for a full list of functions.

The Pro Git book, by Scott Chacon, is an excellent resource to teach you the inner workings of Git.

help.github and GitHub Training are also great for anything related to Git in general and using Git with GitHub.