Getting Started With Git and GitHub

Explaining Git and GitHub. Forked from Jaime Kosoy. The following commands below are to be run in the Terminal.App for Mac OSX or Linux. For a good overview on how to use the Terminal see this tutorial. There is also a [desktop application](desktop application) for GitHub if you'd prefer to not use the Terminal.App.

Some links for more in depth learning

Hands on / interactive learning

• Learn Version Control with Git A website for learning Git. Appears to cost money but has a free html book.
• Git Immersion A website with tutorial materials you download and follow along with.
• Try Git A 15 minute interactive tutorial to learn the basics.
• Git-it Interactive software you run from the Terminal (requires installing node.js and nmp).

Purely text based resources

• Git: No Deep Sh*t A super simplified way of explaining git, basically a cheatsheet.
• The Git Book Explains everything that's possible with git in lots and lots of detail.

The Git Flow

The following snippet is designed to explain Vincent Driessen's git branching model, at least as well as I understand it. Special thanks to Stephen Koch for being the true master here.

A way to think about Git and Github.

Milestones of milestones of milestones. In other words:

• Open up a text editor.

• Type "Hello World".

• Save this file.

  • You have now created a "milestone" on your hard drive of this text.
    • You can now retreive that milestone by double clicking it to re-open it in your text editor.
    • This should be a concept you already understand quite well.

• Change the contents of that file again. Add in your own text. Save it again.

  • By saving it again you've overwritten the previous milestone.
  • You can certainly redo the work (e.g. replacing all the text with "Hello World" and saving again) but the original work is gone otherwise.

• Git saves milestones of milestones.

    git commit -am "By typing this command I am saving a collection of saved files."
  

• This is great because now we can roll back to old versions of files without having to retype. Aka "source control".

• However, wouldn't it be great if we could further save milestones in the cloud?

  • Aka milestones of milestones of milestones.
    • Github -> Git -> Save

• Github is two things:

  • git, in the cloud
  • a social network around source code

• All you need to do to push to Github:

    git push origin master
  

• Now one could "clone" that repository on another computer and not just get the latest code but the complete revision history on another computer.

Setting up

Assuming your project is in a folder named "Project" on your Desktop.

Starting from scratch

cd ~/Desktop/Project
git init
git checkout -b develop
touch README.md

• Open the README.md file you just created in your text editor. Describe your project. I've provided a basic template below for what it's worth. Save it.

• Go to Github (or Bitbucket or whereever you want to save your code in the cloud). Create a new project.

  • If you're on Github, do not check Initialize this project with a README since you just made one.

• Determine your SSH clone url. On Github it's probably something like git@github.com:USERNAME/PROJECT.git. Should be on the project's page somewhere.

• Add your remote.

    git remote add origin {{the link you just copied}}
  

• Breaking that down

  • git :: The git command
  • remote add :: We're adding a remote connection for this repository
  • origin :: We're naming the remote "origin". You can also call this "github" or "bananasauraus" if you'd like.

Cloning an existing repository.

• Determine your SSH clone url. On Github it's probably something like git@github.com:USERNAME/PROJECT.git. Should be on the project's page somewhere.

    cd ~/Desktop
    git clone {{the link you just copied}} Project
  

• This creates a directory named "Project", clones the repository there and adds a remote named "origin" back to the source.

    cd Project
    git checkout develop
  

• If that last command fails

    git checkout -b develop
  

Updating/The Development Cycle

You now have a git repository, likely with two branches: master and develop. Now bake these laws into your mind and process:

####You will never commit to master directly. ####You will never commit to develop directly.

Instead, you will create feature branches on your machine that exist for the purpose of solving singular issues. You will always base your features off the develop branch.

	git checkout develop
	git checkout -b my-feature-branch

This last command creates a new branch named "my-feature-branch" based off of develop. You can name that branch whatever you like. You should not have to push it to Github unless you intend to work on multiple machines on that feature.

Make changes.

git add .
git commit -am "I have made some changes."

This adds any new files to be tracked and makes a commit. Now let's add them to develop.

git checkout develop
git merge --no-ff my-feature-branch
git push origin develop

Releasing

Finished with your project?

• Create a feature branch as normal.

• Update the version history in the README.md file

• Update this to develop as normal.

    git checkout master
    git merge --no-ff develop
    git push origin master
    git tag v1.0.0
    git push origin v1.0.0
  

Replace 1.0.0 in the snippet here with your appropriate versions. Now you have a tag saved.