Git Commands Guide

This guide explains the basic Git commands for connecting to a GitHub repository and managing your code changes.

Initial Setup

1. Configure Git

First-time setup on your computer:

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

2. Initialize a Repository

Choose one of these methods:

Create a New Repository

# Create and enter your project folder
mkdir your-project
cd your-project

# Initialize Git
git init

Clone an Existing Repository

git clone https://github.com/username/repository-name.git

Basic Workflow

1. Check Status

See which files have been changed:

git status

2. Add Files

# Add specific file
git add filename.ext

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

# Add all changes
git add .

3. Commit Changes

# Commit with a message
git commit -m "Your descriptive commit message"

# Add and commit in one command (for tracked files only)
git commit -am "Your descriptive commit message"

4. Push Changes

# First time push
git push -u origin main

# Subsequent pushes
git push

Working with Remotes

Add Remote Repository

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

# View remote repositories
git remote -v

Switch Branch

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

# Switch to an existing branch
git checkout branch-name

Common Commands

View Changes

# See uncommitted changes
git diff

# See commit history
git log

Undo Changes

# Undo changes in a file
git checkout filename.ext

# Reset staged changes
git reset filename.ext

# Reset all changes to last commit
git reset --hard

Update Local Repository

# Fetch and merge changes
git pull

# Fetch changes without merging
git fetch

Best Practices

1. Commit Often: Make small, focused commits
2. Write Clear Messages: Use descriptive commit messages
3. Pull Before Push: Always pull before pushing to avoid conflicts
4. Use Branches: Create branches for new features
5. Review Changes: Check git status and git diff before committing

Handling Errors

Fix Wrong Commit Message

# Fix last commit message
git commit --amend -m "New message"

Undo Last Commit

# Undo commit but keep changes
git reset --soft HEAD~1

# Undo commit and discard changes
git reset --hard HEAD~1

GitHub Authentication

Using Personal Access Token

1. Go to GitHub Settings
2. Select Developer Settings
3. Generate Personal Access Token
4. Use token instead of password when pushing

Using SSH

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

# Add SSH key to GitHub account
# Copy the public key (.pub file) to GitHub settings

Need Help?

• View command help: git help command
• View command options: git command -h
• Check Git documentation: Git Documentation
• GitHub Guides: GitHub Guides