Git Version Control System Guide

Git is a distributed version control system that helps track changes in source code during software development. It enables multiple developers to work together on projects efficiently while maintaining a complete history of changes.

Key Features

• Distributed version control
• Branching and merging capabilities
• Complete history tracking
• Support for collaborative development
• Submodule support for project dependencies

Basic Commands

Repository Setup

# Initialize a new repository
git init

# Clone an existing repository
git clone https://github.com/username/repository.git

# Add remote repository
git remote add origin https://github.com/username/repository.git

Daily Operations

# Check repository status
git status

# Stage changes
git add filename
git add .  # Stage all changes

# Commit changes
git commit -m "Descriptive commit message"

# Push changes to remote
git push origin branch-name

# Pull latest changes
git pull origin branch-name

Branch Management

# Create new branch
git checkout -b feature-branch

# List all branches
git branch -a

# Switch branches
git checkout branch-name

# Merge branches
git merge feature-branch

# Delete branch
git branch -d branch-name

Working with Submodules

Submodules allow you to keep a Git repository as a subdirectory of another Git repository, useful for managing project dependencies or shared components.

Adding a Submodule

# Add a submodule to your project
git submodule add https://github.com/username/library.git path/to/submodule

# Initialize submodule
git submodule init

# Update submodule to latest commit
git submodule update

Updating Submodules

# Update all submodules to their latest commits
git submodule update --remote

# Pull changes with submodules when cloning
git clone --recurse-submodules repository-url

Additional Tips

• Commit Messages: Write clear, descriptive commit messages that explain what changes were made and why
• Branching Strategy: Use feature branches for new development to keep main/master branch stable
• Submodule Management:
  • Always commit submodule changes separately from main project changes
  • Use specific commits or tags for submodules to ensure stability
  • Update submodules carefully to avoid breaking changes

Common Use Cases

Reverting Changes

# Discard changes in working directory
git checkout -- filename

# Reset staged changes
git reset HEAD filename

# Revert a commit
git revert commit-hash

Stashing Changes

# Save changes temporarily
git stash

# List stashed changes
git stash list

# Apply stashed changes
git stash pop

Viewing History

# View commit history
git log

# View changes in commit
git show commit-hash

# View file changes
git diff filename

This guide covers the most common Git operations for daily development work. For more detailed information about specific commands or advanced usage, consult the official Git documentation.