Sameh Attia: A step-by-step guide to Git

Monday, January 29, 2018

A step-by-step guide to Git

https://opensource.com/article/18/1/step-step-guide-git

Don't be nervous. This beginner's guide will quickly and easily get you started using Git.

Image by :

Internet Archive Book Images. Modified by Opensource.com. CC BY-SA 4.0

If you've never used Git, you may be nervous about it. There's nothing to worry about—just follow along with this step-by-step getting-started guide, and you will soon have a new Git repository hosted on GitHub.
Before we dive in, let's clear up a common misconception: Git isn't the same thing as GitHub. Git is a version-control system (i.e., a piece of software) that helps you keep track of your computer programs and files and the changes that are made to them over time. It also allows you to collaborate with your peers on a program, code, or file. GitHub and similar services (including GitLab and BitBucket) are websites that host a Git server program to hold your code.

Step 1: Create a GitHub account

The easiest way to get started is to create an account on GitHub.com (it's free).

git_guide1.png

Pick a username (e.g., octocat123), enter your email address and a password, and click Sign up for GitHub. Once you are in, it will look something like this:

git_guide2.png

Step 2: Create a new repository

A repository is like a place or a container where something is stored; in this case we're creating a Git repository to store code. To create a new repository, select New Repository from the + sign dropdown menu (you can see I've selected it in the upper-right corner in the image above).

git_guide3.png

Enter a name for your repository (e.g, "Demo") and click Create Repository. Don't worry about changing any other options on this page.
Congratulations! You have set up your first repo on GitHub.com.

Step 3: Create a file

Once your repo is created, it will look like this:

git_guide4.png

Don't panic, it's simpler than it looks. Stay with me. Look at the section that starts "...or create a new repository on the command line," and ignore the rest for now.
Open the Terminal program on your computer.

git_guide5.png

Type git and hit Enter. If it says command bash: git: command not found, then install Git with the command for your Linux operating system or distribution. Check the installation by typing git and hitting Enter; if it's installed, you should see a bunch of information about how you can use the command.
In the terminal, type:

mkdir Demo

This command will create a directory (or folder) named Demo.
Change your terminal to the Demo directory with the command:

cd Demo

Then enter:

echo "#Demo" >> README.md

This creates a file named README.md and writes #Demo in it. To check that the file was created successfully, enter:

cat README.md

This will show you what is inside the README.md file, if the file was created correctly. Your terminal will look like this:

git_guide7.png

To tell your computer that Demo is a directory managed by the Git program, enter:

git init

Then, to tell the Git program you care about this file and want to track any changes from this point forward, enter:

git add README.md

Step 4: Make a commit

So far you've created a file and told Git about it, and now it's time to create a commit. Commit can be thought of as a milestone. Every time you accomplish some work, you can write a Git commit to store that version of your file, so you can go back later and see what it looked like at that point in time. Whenever you make a change to your file, you create a new version of that file, different from the previous one. To make a commit, enter:

git commit -m "first commit"

That's it! You just created a Git commit and included a message that says first commit. You must always write a message in commit; it not only helps you identify a commit, but it also enables you to understand what you did with the file at that point. So tomorrow, if you add a new piece of code in your file, you can write a commit message that says, Added new code, and when you come back in a month to look at your commit history or Git log (the list of commits), you will know what you changed in the files.

Step 5: Connect your GitHub repo with your computer

Now, it's time to connect your computer to GitHub with the command:

git remote add origin https://github.com//Demo.git

Let's look at this command step by step. We are telling Git to add a remote called origin with the address https://github.com//Demo.git (i.e., the URL of your Git repo on GitHub.com). This allows you to interact with your Git repository on GitHub.com by typing origin instead of the full URL and Git will know where to send your code. Why origin? Well, you can name it anything else if you'd like.
Now we have connected our local copy of the Demo repository to its remote counterpart on GitHub.com. Your terminal looks like this:

git_guide8.png

Now that we have added the remote, we can push our code (i.e., upload our README.md file) to GitHub.com.
Once you are done, your terminal will look like this:

git_guide9.png

And if you go to https://github.com//Demo you will see something like this:

git_guide10.png

That's it! You have created your first GitHub repo, connected it to your computer, and pushed (or uploaded) a file from your computer to your repository called Demo on GitHub.com. Next time, I will write about Git cloning (downloading your code from GitHub to your computer), adding new files, modifying existing files, and pushing (uploading) files to GitHub.