⚙️ Git Installation and Initial Setup

Why Git, Specifically?

Git is the distributed version control system Linus Torvalds built in 2005 for Linux kernel development. Its original design goals still explain why it won:

• Speed: most operations are local, so they're near-instant even on huge projects.
• Simple internal model: a content-addressed store of snapshots, which makes it fast and tamper-evident.
• Cheap branching & merging: non-linear development is the normal case, not a special one.
• Fully distributed: no mandatory central server; every clone is complete.
• Scale: it handles thousands of contributors on a single codebase.

Add the ecosystem — GitHub, GitLab, Bitbucket, and deep editor integration — and Git is the near-universal default. Installing it is your entry ticket to nearly every modern codebase.

Installing Git by OS

Git runs everywhere. Find your operating system below, run the install, and then verify.

Windows

The recommended route is Git for Windows, which bundles Git, Git Bash, and the Credential Manager. Download the installer from git-scm.com/download/win and accept the defaults, with two choices worth noting:

• PATH option: choose "Git from the command line and also from 3rd-party software."
• Line endings: choose "Checkout Windows-style, commit Unix-style line endings."

Prefer a Linux environment on Windows? Install WSL (Windows Subsystem for Linux) and use its package manager instead:

# In an elevated PowerShell, install WSL + Ubuntu:
wsl --install

# Then, inside your Ubuntu shell:
sudo apt update
sudo apt install git

macOS

The cleanest option is Homebrew:

# Install Homebrew first if you don't have it:
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

# Then install Git:
brew install git

Alternatively, running any git command triggers macOS to offer the Xcode Command Line Tools, which include Git. The official installer at git-scm.com/download/mac also works.

Linux

Use your distribution's package manager:

# Debian / Ubuntu
sudo apt update && sudo apt install git

# Fedora
sudo dnf install git

# Arch
sudo pacman -S git

# RHEL / CentOS
sudo yum install git

Verify the install

On any OS, open a terminal and run:

git --version

git version 2.44.0

If you see a version number, Git is installed and on your PATH. If the command isn't found, jump to Troubleshooting.

Initial Configuration

Git reads settings from three levels, each overriding the one above it, so a repo setting beats your user setting, which beats the system default:

Set your identity (do this first)

Git stamps every commit with a name and email. Use the email tied to your GitHub/GitLab account:

git config --global user.name "Your Name"
git config --global user.email "your.email@example.com"

Recommended settings

These four make Git noticeably more pleasant and are worth setting once, globally:

# Name the initial branch "main" (modern default)
git config --global init.defaultBranch main

# Use VS Code as the editor for commit messages (--wait is important)
git config --global core.editor "code --wait"

# Line-ending handling: "true" on Windows, "input" on macOS/Linux
git config --global core.autocrlf true      # Windows
git config --global core.autocrlf input     # macOS / Linux

# Cache credentials so you don't retype them constantly
git config --global credential.helper manager   # Windows (Git Credential Manager)
git config --global credential.helper osxkeychain # macOS

Handy aliases

Aliases turn frequent commands into short ones:

git config --global alias.st status
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.lg "log --oneline --graph --decorate --all"

Now git st runs git status, and git lg draws a compact, graphical history.

Inspect your configuration

git config --list                 # every active setting
git config user.name              # one specific value
git config --show-origin user.email  # which file defined it

A Global .gitignore

Some files should never be committed to any repository — OS cruft like .DS_Store and editor folders like .idea/. Rather than repeat those patterns in every project, set them once globally.

Create ~/.gitignore_global with contents like:

# OS files
.DS_Store
Thumbs.db

# Editor / IDE
.idea/
.vscode/
*.swp

# Logs and local databases
*.log
*.sqlite

Then tell Git to always honor it:

git config --global core.excludesfile ~/.gitignore_global

The Three States of Git

Everything you do in Git makes more sense once you internalize that a file lives in one of three areas. A change flows left to right:

• Modified: you changed a file in the working directory but haven't staged it.
• Staged: you marked the change to go into the next commit.
• Committed: the snapshot is safely stored in your local repository.

That staging step — unique among common VCSs — is what lets you commit exactly the changes that belong together, even if your working directory holds more.

Your First Repository

Let's turn a folder into a repository and make two commits. Type each command and read the output — the messages teach you as much as the commands.

# 1. Create and enter a project folder
mkdir my-project
cd my-project

# 2. Turn it into a Git repository
git init

# 3. Create a file
echo "# My Project" > README.md

# 4. See what Git notices (README.md is "untracked")
git status

# 5. Stage the file, then commit it
git add README.md
git commit -m "Add project README"

# 6. Make a change and commit it in one step (works for tracked files)
echo "A sample project for learning Git." >> README.md
git commit -am "Describe the project in the README"

# 7. Review your history
git log --oneline

a1b2c3d Describe the project in the README
e4f5g6h Add project README

Working on an existing project instead? You'd clone it rather than init:

git clone https://github.com/octocat/Hello-World.git
cd Hello-World

Cloning downloads the full repository — every file and its entire history — and sets up the remote automatically.

Troubleshooting

A few first-run snags and their fixes:

Git also has excellent built-in help — reach for it before searching the web:

git help config          # full manual for a command
git config -h            # quick option summary

Hands-on Exercise

git --version

git config --global user.name "Ada Lovelace"
git config --global user.email "ada@example.com"
git config --global init.defaultBranch main
git config --global alias.st status
git config --global alias.lg "log --oneline --graph --decorate --all"
git config --global core.excludesfile ~/.gitignore_global

mkdir git-practice && cd git-practice
git init
echo "# Git Practice" > README.md
git add README.md
git commit -m "Add project README"
echo "Learning Git setup." >> README.md
git commit -am "Expand README with a description"
git lg

Quick Quiz

Summary & What's Next

📚 Further Reading

• Pro Git — First-Time Git Setup
• GitHub Docs — Getting started with Git
• GitHub's collection of .gitignore templates

🚀 What's Next?

Git is installed and configured, and you've made your first commits. Next we'll drill the core day-to-day commands — status, add, commit, diff, log, and the ways to undo mistakes — until they're second nature.