By the end of this chapter, you should be able to:
If you google "what is git" you will probably see the definition for "an unpleasant or contemptible person." Thankfully, Git is much better than that. According to the Git documentation:
Git is a free and open source distributed version control system designed to handle everything from small to very large projects with speed and efficiency.
In plain English, Git is a tool that allows developers to track versions of their code over time. It does this by creating "snapshots" of the current state of the code base whenever you tell it to. Put simply, Git is essential when collaborating with other developers to ensure that previous "snapshots" of the code can be revisited if necessary. For example, if you are working on the code and accidentally break the app, it's much easier if you're using Git and can simply roll back to a previous version of the code. Otherwise, you'd have to remember all the changes you made, and manually undo them; for an application of even moderate complexity, this simply isn't feasible.
When you're learning about tools like Git, you'll often see the acronym VCS. This stands for Version Control System. Git is a VCS because it lets you create different versions of your code and easily swap back and forth between different versions. While Git is a hugely popular VCS, it's not the only one. Subversion is another example (a more complete list can be found here).
Before we can get started with anything Git related, we need to make sure you have Git installed. In your terminal, type in
git --version; if you do not see an error, you are good to go. If you are seeing any errors, (e.g.
command not found: git), you may need to install Git on your computer. If you're using a Mac, the best thing to do is to install Homebrew, and then from the terminal run the command
brew install git. (Want to know more about Homebrew? Check out this introduction on Wikipedia.) If you're on Linux, try running
sudo apt-get install git.
Once you have Git installed, you need to "initialize" a repository with Git before you can start using it. Create a folder called
cd into that folder.
Once you are in this folder, run the command
git init and you will see something like
Initialized empty Git repository in /Users/YOUR_USERNAME/Desktop/learn_git/.git/. What does this mean? What do you think just happened? If you type in
ls you will see that it looks like nothing is there... but how can you view hidden files?
After typing in
ls -a you will see a folder called
.git. This is what the
git init command does: it creates a
.git folder for you. Fortunately, you will almost never have to go into that folder, but without it you will not be able to use any of the git commands in the next chapter. So remember, the first step to any project with Git, is making sure you have a
If you accidentally initialize a repository in the wrong directory (you don't want to make your Desktop or Home folder a git repository), you can just remove the
.git folder using
rm -rf .git.
When you're ready, move on to Basic Git Commands