learn-co-curriculum / github-basics

GitHub Basics

Overview

You might have worked with version control software in the past, or this might be your first rodeo. Either way, we're going to teach you enough about git to be dangerous.

This brief overview covers the concepts of cloning, forking, committing, and updating.

git

git is a library that manages your source code. It helps you roll back changes or merge in changes from somewhere/someone else – it's indispensable for working in teams, but you can use it to keep track of solo work, too. Learn leans heavily on git (and GitHub) because it's such a powerful library.

Cloning

git clone SOURCE [DESTINATION] takes the repository specified by SOURCE and copies it locally – by default, to a directory that matches the name of SOURCE, but you can optionally supply another DESTINATION. Try it!

git clone [email protected]:learn-co-curriculum/github-basics.git

This will create a directory called github-basics as a subdirectory of the directory in which you issue the git clone command. Now try this:

git clone [email protected]:learn-co-curriculum/github-basics.git my-github-basics

Now you've cloned the same source code into a directory called my-github-basics. Pretty sweet, eh?

If there are changes made to the source that you've cloned (called master by convention), you can pull:

cd github-basics
git pull

from the root of your local copy to merge those changes in.

Forking

Forking is a feature of GitHub. It lets you create an exact copy of a repository under your name or organization – this way, you can make changes to your fork without modifying the canonical version that so many folks depend on. Learn uses forks for submitting labs.

To fork a repository, simply click the "Fork" button in the top right corner of the GitHub repository page. Try it with this repo. (You might need to click on the GitHub icon in the upper right hand corner of this lesson to go to the source.)

You should see a modal that lets you select your destination organization. Usually you'll want to fork to your personal profile.

Once you've forked the repo, you can clone your fork of it. Cloning sets up the master branch automatically ("branches" are basically namespaces for sets of changes in the source code). You can pull in changes from your fork with a simple git pull; if you'd like to pull in changes from the canonical version, you can track changes there, too – just add it as a remote:

git remote add upstream [email protected]:[organization]/[repo].git

Then you can git fetch upstream and git merge upstream/master to update your local source.

Committing

Commits are units of change in git. It's best to commit as often as possible, but not so often that your git history becomes muddied. Small features make great commits.

Let's try making a commit on your local copy of your fork of this repository. You can change whatever you want – maybe add a line to the README, or a create a dummy file. Save your changes in your preferred text editor, then in your terminal run

git add --all
git commit -am "My first commit!"

What was all of that about? Well, git add adds new files for committing. If a file isn't staged, it won't be tracked in the commit you're about to make.

git commit -am "YOUR MESSGAGE" commits your changes along with the message that you supply. The -a option works the same as the --all option passed to git add, except that it ignores new files — that's why we included the git add --all step. The -m option tells git that you're passing the message next. If you omit -m, git will open a text editor and you'll be able to add your commit message there.

Another handy option to keep in mind is -v. We like to use git commit -av to open a text editor (for adding the message) that has a list of changes below the message input. It's pretty cool!

Updating

Finally, let's update the remote repository:

git push

git push pushes your changes up to the remote repository. If you check your fork, you should see the changes there.

Resources

• git: This book is an excellent resource for everything git-related.

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