Git Version Control

# Initialize a new repository
git init

# Clone an existing repository
git clone <repository-url>

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

# Check configuration
git config --list

# Check repository status
git status

# Stage changes
git add <file>           # Add specific file
git add .                # Add all changes

# Commit changes
git commit -m "Commit message"

# View commit history
git log
git log --oneline        # Compact view
git log --graph          # Visual graph

# List branches
git branch

# Create new branch
git branch <branch-name>

# Switch branch
git checkout <branch-name>
git switch <branch-name>  # Modern syntax

# Create and switch
git checkout -b <branch-name>
git switch -c <branch-name>  # Modern syntax

# Merge branch
git merge <branch-name>

# Delete branch
git branch -d <branch-name>   # Safe delete
git branch -D <branch-name>   # Force delete

# Add remote repository
git remote add origin <repository-url>

# View remotes
git remote -v

# Push to remote
git push origin <branch-name>
git push -u origin <branch-name>  # Set upstream

# Pull from remote
git pull origin <branch-name>

# Fetch updates
git fetch origin

# Push all branches
git push --all origin

# Unstage files
git reset HEAD <file>
git restore --staged <file>  # Modern syntax

# Discard local changes
git checkout -- <file>
git restore <file>           # Modern syntax

# Amend last commit
git commit --amend

# Reset to specific commit
git reset --soft HEAD~1      # Keep changes staged
git reset --mixed HEAD~1     # Keep changes unstaged
git reset --hard HEAD~1      # Discard changes

# Stash changes
git stash
git stash list
git stash pop
git stash drop

# Install GitHub CLI (if not installed)
# macOS: brew install gh
# Windows: winget install --id GitHub.cli

# Authenticate
gh auth login

# Create repository
gh repo create <repo-name>

# Clone repository
gh repo clone <owner>/<repo>

# Create pull request
gh pr create

# View issues
gh issue list

# Generate SSH key
ssh-keygen -t ed25519 -C "your.email@example.com"

# Add to SSH agent
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519

# Copy public key to clipboard
# macOS: pbcopy < ~/.ssh/id_ed25519.pub
# Add to GitHub: Settings → SSH and GPG keys → New SSH key

# Identify conflicted files
git status

# Edit files to resolve conflicts (look for <<<<<<< HEAD)
# Then stage and commit
git add <resolved-files>
git commit -m "Resolve merge conflict"

# Create new branch from detached state
git checkout -b <new-branch-name>

# Or return to previous branch
git checkout <branch-name>