Set up Git

What you will be able to do

Make Git ready to use: install it, give it your name, and make your first repository. After this lesson, Git can record your work in the ticket-notes project.

Before you startWhat to know and to have readyAbout 20 minutes

What you need to know

• How to open a terminal and move between folders with cd, from Terminal bridge: Worked example: find your place and move.

What you need on your computer

• A terminal. On Windows, use Git Bash, which you installed in Terminal bridge: Get a terminal.
• The folder projects in your home folder. You made it in Terminal bridge: Guided practice: make the practice folder. If it is missing, run mkdir ~/projects.
• No practice lab is necessary for this lesson, because you make ticket-notes from nothing in Step 3: make a repository. If it breaks, delete it with rm -rf ~/projects/ticket-notes, then do Step 3 again.

Tested with Git 2.54 on macOS, Windows (Git Bash) and Linux. Any Git version from 2.40 works for this lesson.

A repository is a folder with a history

A repository (or “repo”) is a project folder that Git tracks. It looks like a normal folder, with one addition: a hidden folder called .git. Git keeps the full history of the project in .git.

You do not open or change the .git folder yourself. You use Git commands, and Git updates .git for you. If you delete .git, the folder becomes a normal folder again, and the history is gone.

A repository can exist in more than one place:

• A local repository is on your computer. You work in it, and Git does not need the internet for this work.
• A remote repository (or “remote”) is a copy of the same repository in a different place. Usually it is on a server such as GitHub. Your team shares work through the remote.

Git does not copy your work to a remote automatically. You send and receive changes when you decide to. You learn how in Module 2.

Step 1: check that Git is installed

macOS

1. In the terminal, run:

   git --version

2. If a window asks you to install the “command line developer tools”, select Install. When the installation is complete, run git --version again.

Windows

You installed Git in the previous lesson. In Git Bash, run:

git --version

Linux

1. In the terminal, run:

   git --version

2. If the output is command not found, install Git. On Ubuntu or Debian, run sudo apt install git. On Fedora, run sudo dnf install git. Then run git --version again.

The output shows a version number. Yours can be different:

Output

git version 2.54.0

Step 2: tell Git who you are

Each time you save a change, Git records who made it. Give Git your name and email address once. The --global option means “use this for every repository on this computer”.

Caution

Git stores this email address in every change that you save. Anyone who can see the history can read it. If you do not want to share your personal address, use a different one. Hosting services such as GitHub give you a private address for this.

1. Set your name. Replace Your Name with your name, and keep the quotes:

   git config --global user.name "Your Name"

2. Set your email address. Replace the example address with yours:

   git config --global user.email "you@example.com"

3. Set the name of the first branch in new repositories to main:

   git config --global init.defaultBranch main

   A branch is a line of work in a repository. You learn about branches in Module 2. Most teams now call the first branch main. Some Git versions use master if you do not set this.

4. Check your settings:

   git config --global --list

   The output shows your values:

   user.name=Amira Khan
   user.email=amira@example.com
   init.defaultbranch=main

   Git shows the names in lowercase. This is normal.

If the output has a mistake, run the same git config command again with the correct value. The new value replaces the old one.

Step 3: make a repository

Danger

Before you run git init, run pwd and check where you are. If you run it in your home folder, Git tracks every file in your home folder. If this happens, see the common mistake at the end of this lesson.

1. Move to your projects folder:

   cd ~/projects

2. Make a repository called ticket-notes:

   git init ticket-notes

   Git makes the folder and the .git folder inside it:

   Initialized empty Git repository in /Users/amira/projects/ticket-notes/.git/

3. Move into the repository:

   cd ticket-notes

4. List all the files, including hidden ones. The -a option means “all”:

   ls -a

   .  ..  .git

   The .git folder is there. On some systems, the names are on separate lines. . means “this folder” and .. means “the folder above”.

5. Ask Git about the state of the repository:

   git status

   On branch main
   
   No commits yet
   
   nothing to commit (create/copy files and use "git add" to track)

   You use git status often. It is the safest command in Git, because it only shows information and changes nothing.

Worked example: clone a repository

To clone means to make a full copy of a repository, with its history. When you join a team, you usually clone the team’s repository from a server.

You can also clone from a folder on your own computer. This shows how local and remote repositories connect, without an account on a server. Amira clones ticket-notes into a second folder:

Terminal

cd ~/projects
git clone ticket-notes ticket-notes-copy

Output

Cloning into 'ticket-notes-copy'...
warning: You appear to have cloned an empty repository.
done.

The warning is expected. The original repository has no saved changes yet, so the copy is empty too.

Next, she moves into the copy and asks Git where its remote is. The -v option means “verbose”: show more detail.

Terminal

cd ticket-notes-copy
git remote -v

Output

origin  /Users/amira/projects/ticket-notes (fetch)
origin  /Users/amira/projects/ticket-notes (push)

The copy remembers where it came from. origin is the name that Git gives to the remote that you cloned from. For the copy, ticket-notes is the remote. On a team, origin is usually an address on a server, for example https://github.com/team/ticket-notes.git.

The original ticket-notes has no remote. Run git remote -v in it: the output is empty.

Your turn: inspect the two repositories

Answer these questions with commands, not from memory:

1. In ticket-notes-copy, which branch are you on? Use git status.
2. Does ticket-notes-copy have a .git folder of its own? Use ls -a.
3. Does the original ticket-notes have a remote? Use git remote -v.

When you finish, delete the copy. You do not use it again, and a new clone is easy to make. Go up to projects, then delete the folder:

cd ~/projects
rm -rf ticket-notes-copy

Caution

rm -rf deletes a folder and everything in it, with no undo. Type the folder name carefully, and check it before you press Enter.

Show the answers

1. main. A clone uses the same first branch as the original.
2. Yes. Every clone is a full repository, with its own .git folder and its own history.
3. No. git remote -v shows nothing in ticket-notes, because you made it with git init, not with git clone.

Common mistake

Not a git repository

Symptom: you run a Git command, and Git shows this error:

fatal: not a git repository (or any of the parent directories): .git

Cause: the working directory is not in a repository. Git looks for a .git folder in the working directory and in each folder above it. It did not find one. Usually you are in the wrong folder.

Fix:

1. Run pwd to see where you are.
2. Move into the repository, for example with cd ~/projects/ticket-notes.
3. Run the Git command again.

A related mistake: you ran git init in your home folder. Now git status in your home folder lists all your files as untracked. To fix it, go to your home folder and delete only the .git folder there with rm -rf ~/.git. Check the command before you run it. Your files stay, and only the new, empty history is removed. Do not do this in a real project, because it deletes that project’s history.

Check your understanding

Amira runs git status in /Users/amira/projects. Git shows 'fatal: not a git repository'. But ticket-notes is a repository. Why does she get the error?

Show the answer

The projects folder is not a repository. The repository is the ticket-notes folder inside it. Git looks in the working directory and the folders above it, never in the folders below it. She must run cd ticket-notes first.

Check your understanding

Practical check: show that Git knows your name and email address, and that ticket-notes is a repository with no commits.

Show the answer

Run git config --global --list: the output shows your user.name and user.email. Then run cd ~/projects/ticket-notes and git status: the output shows On branch main and No commits yet.

Recap

• A repository is a folder with a hidden .git folder, which keeps the history.
• You set your name and email address once with git config --global.
• git init makes a new repository. git clone copies a repository that exists, with its history.
• A local repository is on your computer. A remote is a copy in another place. Git connects them only when you tell it to.
• git status shows the state of a repository and changes nothing.

Next, you save your first change in ticket-notes.

Next: Track a first change