Git Installation & Configuration Guide ⚙️

This guide covers installing Git on Windows, macOS, and Linux, followed by essential first-time global configuration and SSH key integration for GitHub/GitLab.

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1. Installing Git

🐧 Linux (Ubuntu / Debian)

# Update package lists
sudo apt update

# Install Git
sudo apt install git -y

# Verify installation
git --version

🐧 Linux (Fedora / RHEL / CentOS)

# Fedora
sudo dnf install git -y

# CentOS / RHEL
sudo yum install git -y

🐧 Linux (Arch Linux)

sudo pacman -S git

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🍎 macOS

Option 1: Via Homebrew (Recommended)

# Install Homebrew if not already installed, then:
brew install git

# Verify installation
git --version

Option 2: Via Xcode Command Line Tools

xcode-select --install

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💻 Windows

Option 1: Official Installer (Git for Windows)

1. Download from git-scm.com/download/win.
2. Run the .exe installer.
3. Recommended settings during setup:
4. Default Editor: VS Code or Vim.
5. Default Branch Name: Choose main.
6. PATH environment: Select "Git from the command line and third-party software".
7. Line ending conversion: "Checkout Windows-style, commit Unix-style" (core.autocrlf = true).
8. Terminal emulator: Use MinTTY.

Option 2: Via Winget

winget install --id Git.Git -e --source winget

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2. First-Time Configuration

Git uses configuration files at 3 different levels: 1. System (--system): Applies to all users on the machine (/etc/gitconfig). 2. Global (--global): Applies to your OS user account (~/.gitconfig). 3. Local (--local): Applies to the specific repository (.git/config).

Essential Global Setup (Mandatory)

# Set your name (appears in commit history)
git config --global user.name "Your Name"

# Set your email (must match your GitHub/GitLab email)
git config --global user.email "your.email@example.com"

# Set default branch name to 'main'
git config --global init.defaultBranch main

# Set default text editor (VS Code, Vim, Nano, etc.)
git config --global core.editor "code --wait"

# Enable colored command output
git config --global color.ui auto

# Configure line ending preferences
# On Windows:
git config --global core.autocrlf true
# On macOS / Linux:
git config --global core.autocrlf input

Verify Configuration

# View all active configuration options
git config --list

# Show configuration sources
git config --list --show-origin

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3. SSH Key Setup for GitHub / GitLab

SSH keys allow secure authentication without typing your password/PAT repeatedly.

Step 1: Generate a new SSH Key Pair

ssh-keygen -t ed25519 -C "your.email@example.com"

Press Enter to accept default location (~/.ssh/id_ed25519). Optionally enter a passphrase.

Step 2: Start SSH Agent & Add Key

# Start background agent
eval "$(ssh-agent -s)"

# Add SSH key to agent
ssh-add ~/.ssh/id_ed25519

Step 3: Copy Public Key

# Linux
cat ~/.ssh/id_ed25519.pub

# macOS
pbcopy < ~/.ssh/id_ed25519.pub

# Windows (Git Bash)
cat ~/.ssh/id_ed25519.pub | clip

Step 4: Add Key to GitHub / GitLab

1. Go to GitHub Settings -> SSH and GPG keys.
2. Click New SSH Key.
3. Paste the key title and string, then save.

Step 5: Test Connection

ssh -T git@github.com

Expected output: Hi username! You've successfully authenticated...