Git and GitHub

Lab Sessions

Installation and Configuration

Installation

• macOS: Install Xcode Command Line Tools. Open Terminal and run:

xcode-select --install

• Linux: Git may already be installed. If not, install it using:

sudo apt install git

• Windows: Download Git for Windows from
  https://git-scm.com/download/win and install it with default settings.

To verify that Git is installed, run:

git --version

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Sign Up for GitHub

Follow these steps to create a GitHub account:

1. Open the GitHub website:
   https://github.com/

2. Click Sign up in the top-right corner.

3. Enter your:

   • Email address
     
   • Password
     
   • Username

4. Choose your email verification preferences.

5. Complete the verification challenge.

6. Click Create account.

7. GitHub will send a verification code to your email. Enter the code to activate your account.

8. Choose the Free plan (sufficient for this course).

After this, your GitHub account is fully ready.

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Git Configuration

Check Current Git Config

Run the following command to see your current configuration (should be mostly empty on new installations):

git config --global --list

Set Username

git config --global user.name "your_name"

Set Email

git config --global user.email "your_email"

Verify Updated Config

Check again:

git config --global --list

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Generate Personal Access Token (PAT)

GitHub no longer accepts passwords for Git operations.
You must generate a Personal Access Token (PAT).

Steps

1. Sign in to your GitHub account.

2. Navigate to:
   Profile → Settings → Developer settings → Personal access tokens → Tokens (classic)

3. Click Generate new token.

4. Select scopes (minimum recommended):

   • repo
   • read:org
   • workflow
   • or simply select all

5. Set No expiration.

6. Click Generate token.

7. Copy the token and store it securely.

You will paste this token when executing:

git push

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Generate SSH Key (Optional but Recommended)

SSH keys allow secure password-less authentication with GitHub.

Steps

1. Open Terminal or PowerShell.

2. Generate a new SSH key:

ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

3. When prompted for a location, press ENTER to use the default:

~/.ssh/id_rsa

4. When asked for a passphrase:
   • leave empty for no passphrase
     
   • or enter a secure passphrase
5. Display your public key:

cat ~/.ssh/id_rsa.pub

Copy SSH Key

macOS:

pbcopy < ~/.ssh/id_rsa.pub

Windows PowerShell:

Get-Content ~/.ssh/id_rsa.pub | Set-Clipboard

Add SSH Key to GitHub

1. Go to GitHub → Settings → SSH and GPG keys
2. Click New SSH key
3. Paste your key
4. Save

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Create a Remote Repository on GitHub

1. Log in to your GitHub account.
2. Click the New repository button.
3. Fill in:
   • Repository name
     
   • Description (optional)
     
   • Set it to Public
4. Do NOT initialize with README (we will create files locally).
5. Click Create repository.

GitHub will show you the remote URL, e.g.:

https://github.com/username/myrepo.git

1. Choose a folder on your computer.
2. Initialize Git in that folder:

git init

3. Connect your local repo to the remote repo:

git remote add origin https://github.com/username/myrepo.git

4. Verify remote:

git remote -v

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Adding a Dummy File

Inside your local project folder, create a simple file:

echo "This is a test file" > test.txt

Then stage it:

git add test.txt

Commit it:

git commit -m "Add test file"

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Pushing to GitHub

Push your commit to GitHub:

git push -u origin main

If your default branch is master, use:

git push -u origin master

You will be asked for:

• username
  
• Personal Access Token (instead of password)

After authentication, your file will appear on GitHub.

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Pulling Changes from GitHub

If changes have been made remotely, you can update your local repo:

git pull origin main

or:

git pull

Use pull whenever you want your local files to match GitHub.

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Cloning a Repository (Alternative Workflow)

Instead of creating a folder manually, you can clone an existing remote repo:

git clone https://github.com/username/myrepo.git

This will:

• Create the folder
  
• Download all existing files
  
• Set the remote origin automatically

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Summary Workflow

1. Create repo on GitHub (empty, no README)
   
2. git init locally
   
3. Create files
   
4. git add
   
5. git commit
   
6. git remote add origin <url>
   
7. git push

or use:

• git clone → edit → git add → git commit → git push

Homework

This task ensures that you can create repositories, work locally, work remotely, and synchronize changes between GitHub and your machine.

Follow the steps below exactly in order.

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Create a Remote Repository on GitHub

1. Log in to your GitHub account.
2. Click New Repository.
3. Set:
   • Repository name: `choose any name
     
   • Visibility: Public
4. Do NOT initialize with README.
5. Click Create Repository.

Copy your remote URL, e.g.:

https://github.com/yourusername/myrepo.git

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Clone the Repository to Your Computer

In a folder of your choice, open Terminal or PowerShell and run:

git clone https://github.com/yourusername/myrepo.git

This will create a new local folder with the repository inside.

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Create a Dummy File Locally

Navigate into the cloned folder:

cd myrepo

Create a simple text file:

echo "This is my first Git test file." > test.txt

Stage and commit the file:

git add test.txt
git commit -m "Add test file"

Push it to GitHub:

git push

Check GitHub — you should now see test.txt in the repository.

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Add a New File on GitHub (Remote)

1. Open your repo on GitHub.
2. Click Add file → Create new file.
3. Name it: remote_file.txt
4. Add any text inside it.
5. Commit the new file.

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Pull the New File to Your Computer

Return to your local repo folder and run:

git pull

You should now see remote_file.txt in your local directory.

This confirms that your local and remote repositories are synchronized.

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Submission

Submit your GitHub repository and GitHub profile links here.

Example format:

https://github.com/yourusername/myrepo