Complete Git Guide

🔧 Setup & Configuration

Initial Setup

Before using Git, configure your identity:

bash

# Set your name and email globally
git config --global user.name "Your Name"
git config --global user.email "your.email@example.com"

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

# Set your preferred editor
git config --global core.editor "code --wait"  # VS Code
git config --global core.editor "vim"          # Vim
git config --global core.editor "nano"         # Nano

Viewing Configuration

bash

# View all configurations
git config --list

# View specific configuration
git config user.name
git config user.email

# View configuration with location info
git config --list --show-origin

💡 Configuration Levels

--system: System-wide configuration (all users)
--global: User-specific configuration
--local: Repository-specific configuration (default)

📁 Repository Operations

Creating Repositories

bash

# Initialize a new repository in current directory
git init

# Initialize with specific branch name
git init --initial-branch=main

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

# Clone to a specific directory
git clone <repository-url> <directory-name>

# Clone a specific branch
git clone -b <branch-name> <repository-url>

# Clone with limited history (shallow clone)
git clone --depth 1 <repository-url>

Repository Information

bash

# Show remote repositories
git remote -v

# Show repository statistics
git count-objects -v

# Show repository size
du -sh .git/

🔄 Basic Workflow

Checking Status

bash

# Check repository status (detailed)
git status

# Check status in short format
git status -s

# Check status and show ignored files
git status --ignored

Status Indicators in Short Format:

?? - Untracked files
A - Added (staged)
M - Modified
D - Deleted
R - Renamed
C - Copied

Adding Files (Staging)

bash

# Add specific file
git add <filename>

# Add multiple files
git add file1.txt file2.txt

# Add all files in current directory
git add .

# Add all files with specific extension
git add *.js

# Add files interactively
git add -i

# Add parts of a file (patch mode)
git add -p <filename>

# Add all tracked files (excluding untracked)
git add -u

Committing Changes

bash

# Commit staged changes with message
git commit -m "Your commit message"

# Commit all tracked files (skip staging)
git commit -am "Your commit message"

# Commit with detailed message
git commit -m "Brief summary" -m "Detailed explanation"

# Commit and open editor for message
git commit

# Amend the last commit
git commit --amend

# Amend without changing message
git commit --amend --no-edit

🌳 Branching & Merging

Branch Management

bash

# List all local branches
git branch

# List all branches including remote
git branch -a

# Create new branch
git branch <branch-name>

# Create and switch to new branch
git checkout -b <branch-name>

# Switch to existing branch
git checkout <branch-name>

# Switch to previous branch
git checkout -

# Rename current branch
git branch -m <new-branch-name>

# Delete merged branch
git branch -d <branch-name>

# Force delete branch (even if not merged)
git branch -D <branch-name>

Merging Strategies

bash

# Fast-forward merge (default when possible)
git merge <branch-name>

# Create merge commit even if fast-forward is possible
git merge --no-ff <branch-name>

# Squash merge (combine all commits into one)
git merge --squash <branch-name>

# Abort ongoing merge
git merge --abort

# Continue merge after resolving conflicts
git merge --continue

🔧 Handling Merge Conflicts

Step 1: Git marks conflicted files
Step 2: Edit files to resolve conflicts
Step 3: Remove conflict markers (<<<<<<<, =======, >>>>>>>)
Step 4: Stage resolved files: git add <filename>
Step 5: Complete merge: git commit

🌐 Remote Operations

Remote Repository Management

bash

# List remote repositories
git remote -v

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

# Remove remote
git remote remove <remote-name>

# Rename remote
git remote rename <old-name> <new-name>

# Change remote URL
git remote set-url <remote-name> <new-url>

# Show remote information
git remote show <remote-name>

Fetching and Pulling

bash

# Fetch from default remote
git fetch

# Fetch from specific remote
git fetch <remote-name>

# Fetch all remotes
git fetch --all

# Fetch and prune deleted branches
git fetch --prune

# Pull changes (fetch + merge)
git pull

# Pull with rebase instead of merge
git pull --rebase

# Pull and automatically stash/unstash changes
git pull --autostash

Pushing Changes

bash

# Push to default remote and branch
git push

# Push to specific remote and branch
git push <remote-name> <branch-name>

# Push and set upstream tracking
git push -u <remote-name> <branch-name>

# Push all branches
git push --all

# Push tags
git push --tags

⚠️ Dangerous Operations

bash

# Force push (dangerous - rewrites history)
git push --force

# Safer force push (fails if remote has new commits)
git push --force-with-lease

# Delete remote branch
git push <remote-name> --delete <branch-name>

📜 Viewing History

Basic Log Commands

bash

# View commit history
git log

# Compact one-line format
git log --oneline

# Show graphical representation
git log --graph

# Combine graph with oneline
git log --graph --oneline --all

# Show file statistics
git log --stat

# Show actual changes
git log --patch

# Limit number of commits
git log -n 5
git log -5

Advanced Log Filtering

bash

# Filter by author
git log --author="John Doe"

# Filter by date range
git log --since="2023-01-01"
git log --until="2023-12-31"
git log --since="2 weeks ago"

# Filter by commit message
git log --grep="bug fix"

# Filter by file
git log -- <filename>
git log --follow -- <filename>  # Follow renames

# Filter by content changes
git log -S "function_name"      # When function_name was added/removed
git log -G "regex_pattern"      # When pattern was added/removed

Comparing Changes

bash

# Show unstaged changes
git diff

# Show staged changes
git diff --staged
git diff --cached

# Compare specific commits
git diff <commit1> <commit2>

# Compare branches
git diff <branch1> <branch2>

# Show changes introduced by a commit
git show <commit-hash>

# Show file at specific commit
git show <commit>:<filename>

↩️ Undoing Changes

Working Directory Changes

bash

# Discard changes in specific file
git checkout -- <filename>

# Discard all changes in working directory
git checkout -- .

# Restore file from specific commit
git checkout <commit> -- <filename>

# Using newer restore command (Git 2.23+)
git restore <filename>
git restore --staged <filename>  # Unstage
git restore --source=<commit> <filename>

Cleaning Untracked Files

bash

# Remove untracked files
git clean -f

# Remove untracked files and directories
git clean -fd

# Preview what will be removed
git clean -n

# Interactive clean
git clean -i

# Remove ignored files too
git clean -fx

Commit History Changes

bash

# Undo last commit, keep changes staged
git reset --soft HEAD~1

# Undo last commit, keep changes in working directory
git reset --mixed HEAD~1
git reset HEAD~1  # default is --mixed

# Undo last commit, discard all changes
git reset --hard HEAD~1

# Reset to specific commit
git reset --hard <commit-hash>

# Create new commit that undoes changes
git revert <commit-hash>

# Revert merge commit
git revert -m 1 <merge-commit-hash>

📦 Stashing

Basic Stashing

bash

# Stash current changes
git stash
git stash push  # newer syntax

# Stash with message
git stash save "Work in progress on feature X"
git stash push -m "Work in progress on feature X"

# Stash including untracked files
git stash -u
git stash --include-untracked

# Stash only specific files
git stash push <filename>

Managing Stashes

bash

# List all stashes
git stash list

# Show stash content
git stash show
git stash show -p  # show patch

# Apply latest stash
git stash apply

# Apply specific stash
git stash apply stash@{2}

# Pop stash (apply and remove)
git stash pop
git stash pop stash@{1}

# Drop specific stash
git stash drop stash@{0}

# Clear all stashes
git stash clear

Advanced Stashing

bash

# Create branch from stash
git stash branch <branch-name> stash@{0}

# Stash only staged changes
git stash --staged

# Interactive stashing
git stash -p

🔄 Common Workflows

Feature Branch Workflow

Update main: git checkout main && git pull origin main
Create feature branch: git checkout -b feature/user-authentication
Work on feature: Make changes, commit regularly
Push feature: git push -u origin feature/user-authentication
Create pull request: Via GitHub/GitLab interface
After approval: Merge and clean up branches

Hotfix Workflow

Create hotfix from main: git checkout -b hotfix/security-patch
Fix critical issue: Make necessary changes
Merge to main: git checkout main && git merge hotfix/security-patch
Tag release: git tag -a v1.2.1 -m "Security hotfix"
Push changes: git push origin main && git push origin v1.2.1
Clean up: Delete hotfix branch

Release Workflow

Create release branch: git checkout -b release/v2.0.0
Finalize release: Version bumps, changelog, etc.
Merge to main: git checkout main && git merge release/v2.0.0
Tag release: git tag -a v2.0.0 -m "Release version 2.0.0"
Merge back to develop: If using GitFlow
Push everything: Main, develop, and tags

⭐ Best Practices

Commit Messages

Follow conventional commit format:

bash

<type>[optional scope]: <description>

[optional body]

[optional footer(s)]

Commit Types:

feat: New feature
fix: Bug fix
docs: Documentation changes
style: Code style changes (formatting, etc.)
refactor: Code refactoring
test: Adding or updating tests
chore: Maintenance tasks

Examples:

bash

feat(auth): add JWT token validation

fix: resolve memory leak in image processing

docs: update API documentation for v2.0

refactor(database): optimize query performance

Branch Naming Conventions

bash

feature/feature-name
bugfix/issue-description
hotfix/critical-issue
release/version-number

🎯 General Guidelines

Commit Often: Make small, focused commits
Write Good Messages: Clear, descriptive commit messages
Use Branches: Separate features, bugs, and experiments
Keep History Clean: Use rebase for feature branches
Test Before Pushing: Ensure code works before sharing
Pull Before Push: Always sync with remote before pushing
Use .gitignore: Exclude unnecessary files
Back Up Important Work: Push branches to remote regularly

Security Considerations

🔒 Security Best Practices

Never commit sensitive data (passwords, API keys, etc.)
Use environment variables for secrets
Review changes before committing
Use signed commits for important repositories
Regularly update Git and related tools
Be cautious with force push operations

Common .gitignore Patterns

bash

# Dependencies
node_modules/
vendor/

# Build outputs
dist/
build/
*.exe
*.dll

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

# OS files
.DS_Store
Thumbs.db

# Logs
*.log
logs/

# Environment files
.env
.env.local

# Temporary files
*.tmp
*.temp

📋 Table of Contents

🔧 Setup & Configuration

Initial Setup

Viewing Configuration

💡 Configuration Levels

📁 Repository Operations

Creating Repositories

Repository Information

🔄 Basic Workflow

Checking Status

Status Indicators in Short Format:

Adding Files (Staging)

Committing Changes

🌳 Branching & Merging

Branch Management

Merging Strategies

🔧 Handling Merge Conflicts

🌐 Remote Operations

Remote Repository Management

Fetching and Pulling

Pushing Changes

⚠️ Dangerous Operations

📜 Viewing History

Basic Log Commands

Advanced Log Filtering

Comparing Changes

↩️ Undoing Changes

Working Directory Changes

Cleaning Untracked Files

Commit History Changes

📦 Stashing

Basic Stashing

Managing Stashes

Advanced Stashing

🔄 Common Workflows

Feature Branch Workflow

Hotfix Workflow

Release Workflow

⭐ Best Practices

Commit Messages

Commit Types:

Examples:

Branch Naming Conventions

🎯 General Guidelines

Security Considerations

🔒 Security Best Practices

Common .gitignore Patterns