The Complete Git & GitHub Guide: Commands Cheatsheet and Authentication Setup

Whether you're just starting your development journey or need a quick reference for Git commands, this guide has you covered. We'll walk through essential Git commands for Linux/Unix systems and show you how to set up GitHub authentication from scratch.

Table of Contents

• Git Basics
• Repository Setup
• Making Changes
• Branching & Merging
• Remote Repositories
• Viewing History & Status
• Undoing Changes
• Advanced Commands
• GitHub Authentication Setup
• Useful Tips & Tricks

Git Basics

Configuration

Set up your Git identity before making any commits:

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1# Set your name and email globally
2git config --global user.name "Your Name"
3git config --global user.email "your.email@example.com"
4
5# View all configuration settings
6git config --list
7
8# Set default branch name to 'main'
9git config --global init.defaultBranch main
10
11# Set your preferred text editor
12git config --global core.editor "nano"  # or vim, code, etc.

Getting Help

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1# Get help for any Git command
2git help <command>
3git <command> --help
4
5# Quick reference
6git <command> -h

Repository Setup

Creating Repositories

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1# Initialize a new Git repository in the current directory
2git init
3
4# Initialize with a specific branch name
5git init -b main
6
7# Clone an existing repository
8git clone <repository-url>
9
10# Clone to a specific directory
11git clone <repository-url> <directory-name>
12
13# Clone only a specific branch
14git clone -b <branch-name> <repository-url>

Making Changes

Staging and Committing

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1# Check the status of your working directory
2git status
3
4# Add specific file to staging area
5git add <file-name>
6
7# Add all changes in current directory
8git add .
9
10# Add all changes in repository
11git add -A
12
13# Add all files with specific extension
14git add *.txt
15
16# Commit staged changes with a message
17git commit -m "Your commit message"
18
19# Add and commit in one step (tracked files only)
20git commit -am "Your commit message"
21
22# Amend the last commit (change message or add forgotten files)
23git commit --amend -m "New commit message"
24
25# Amend without changing the message
26git commit --amend --no-edit

Working with Files

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1# Remove file from working directory and staging area
2git rm <file-name>
3
4# Remove file from staging area only (keep in working directory)
5git rm --cached <file-name>
6
7# Rename or move a file
8git mv <old-name> <new-name>

Branching & Merging

Branch Management

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1# List all local branches
2git branch
3
4# List all branches (local and remote)
5git branch -a
6
7# Create a new branch
8git branch <branch-name>
9
10# Switch to a different branch
11git checkout <branch-name>
12
13# Create and switch to a new branch
14git checkout -b <branch-name>
15
16# Modern way to switch branches (Git 2.23+)
17git switch <branch-name>
18
19# Create and switch to new branch (modern)
20git switch -c <branch-name>
21
22# Delete a branch (safe - prevents deletion if unmerged)
23git branch -d <branch-name>
24
25# Force delete a branch
26git branch -D <branch-name>
27
28# Rename current branch
29git branch -m <new-branch-name>
30
31# Rename a different branch
32git branch -m <old-branch-name> <new-branch-name>

Merging

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1# Merge a branch into current branch
2git merge <branch-name>
3
4# Merge with a custom commit message
5git merge <branch-name> -m "Merge message"
6
7# Abort a merge in progress
8git merge --abort
9
10# Continue merge after resolving conflicts
11git merge --continue

Rebasing

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1# Rebase current branch onto another branch
2git rebase <branch-name>
3
4# Interactive rebase for last N commits
5git rebase -i HEAD~<N>
6
7# Abort a rebase in progress
8git rebase --abort
9
10# Continue rebase after resolving conflicts
11git rebase --continue
12
13# Skip current commit during rebase
14git rebase --skip

Remote Repositories

Working with Remotes

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1# List all configured remotes
2git remote -v
3
4# Add a new remote repository
5git remote add <remote-name> <repository-url>
6
7# Add origin remote (most common)
8git remote add origin https://github.com/username/repo.git
9
10# Remove a remote
11git remote remove <remote-name>
12
13# Rename a remote
14git remote rename <old-name> <new-name>
15
16# Change remote URL
17git remote set-url <remote-name> <new-url>
18
19# Show information about a remote
20git remote show <remote-name>

Fetching and Pulling

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1# Fetch changes from remote (doesn't merge)
2git fetch
3
4# Fetch from specific remote
5git fetch <remote-name>
6
7# Fetch from all remotes
8git fetch --all
9
10# Pull changes from remote (fetch + merge)
11git pull
12
13# Pull from specific remote and branch
14git pull <remote-name> <branch-name>
15
16# Pull with rebase instead of merge
17git pull --rebase

Pushing

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1# Push commits to remote repository
2git push
3
4# Push to specific remote and branch
5git push <remote-name> <branch-name>
6
7# Push and set upstream for current branch
8git push -u origin <branch-name>
9
10# Push all branches to remote
11git push --all
12
13# Push tags to remote
14git push --tags
15
16# Force push (use with caution!)
17git push --force
18
19# Safer force push (won't overwrite others' work)
20git push --force-with-lease
21
22# Delete a remote branch
23git push <remote-name> --delete <branch-name>

Viewing History & Status

Logs and History

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1# View commit history
2git log
3
4# View compact one-line log
5git log --oneline
6
7# View log with graph visualization
8git log --graph --oneline --all
9
10# View last N commits
11git log -n <number>
12
13# View commits by specific author
14git log --author="Author Name"
15
16# View commits in date range
17git log --since="2 weeks ago" --until="yesterday"
18
19# View changes introduced by each commit
20git log -p
21
22# View statistics for each commit
23git log --stat
24
25# View commits that affected a specific file
26git log <file-name>
27
28# Search commits by message
29git log --grep="search term"

Inspecting Changes

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1# Show unstaged changes
2git diff
3
4# Show staged changes
5git diff --staged
6# or
7git diff --cached
8
9# Show changes between branches
10git diff <branch1> <branch2>
11
12# Show changes in a specific file
13git diff <file-name>
14
15# Show changes from a specific commit
16git show <commit-hash>
17
18# Show changes from HEAD
19git show HEAD
20
21# Show file contents from a specific commit
22git show <commit-hash>:<file-path>

Blame and Annotate

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1# Show who changed each line in a file
2git blame <file-name>
3
4# Blame with line numbers
5git blame -L <start-line>,<end-line> <file-name>

Undoing Changes

Unstaging and Reverting

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1# Unstage a file (keep changes in working directory)
2git restore --staged <file-name>
3# or (older method)
4git reset HEAD <file-name>
5
6# Discard changes in working directory
7git restore <file-name>
8# or (older method)
9git checkout -- <file-name>
10
11# Discard all local changes
12git restore .
13
14# Revert a commit (creates a new commit that undoes changes)
15git revert <commit-hash>
16
17# Revert without creating a commit immediately
18git revert -n <commit-hash>

Reset Commands

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1# Reset to a specific commit (keep changes staged)
2git reset --soft <commit-hash>
3
4# Reset to a specific commit (keep changes unstaged)
5git reset --mixed <commit-hash>
6# or simply
7git reset <commit-hash>
8
9# Reset to a specific commit (discard all changes - DANGEROUS!)
10git reset --hard <commit-hash>
11
12# Reset to last commit
13git reset --hard HEAD
14
15# Reset to commit before last
16git reset --hard HEAD~1
17
18# Undo last N commits (keep changes)
19git reset HEAD~<N>

Cleaning

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1# Show what would be removed
2git clean -n
3
4# Remove untracked files
5git clean -f
6
7# Remove untracked files and directories
8git clean -fd
9
10# Remove untracked and ignored files
11git clean -fdx

Advanced Commands

Stashing

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1# Stash current changes
2git stash
3
4# Stash with a message
5git stash save "Work in progress on feature X"
6
7# List all stashes
8git stash list
9
10# Apply most recent stash (keep in stash list)
11git stash apply
12
13# Apply specific stash
14git stash apply stash@{<number>}
15
16# Apply most recent stash and remove from list
17git stash pop
18
19# Drop most recent stash
20git stash drop
21
22# Drop specific stash
23git stash drop stash@{<number>}
24
25# Clear all stashes
26git stash clear
27
28# Show stash contents
29git stash show
30git stash show -p  # Show full diff

Cherry-Picking

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1# Apply a commit from another branch to current branch
2git cherry-pick <commit-hash>
3
4# Cherry-pick multiple commits
5git cherry-pick <commit1> <commit2>
6
7# Cherry-pick a range of commits
8git cherry-pick <commit1>..<commit2>

Tags

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1# List all tags
2git tag
3
4# Create a lightweight tag
5git tag <tag-name>
6
7# Create an annotated tag
8git tag -a <tag-name> -m "Tag message"
9
10# Tag a specific commit
11git tag <tag-name> <commit-hash>
12
13# Push tag to remote
14git push origin <tag-name>
15
16# Push all tags
17git push --tags
18
19# Delete a local tag
20git tag -d <tag-name>
21
22# Delete a remote tag
23git push origin --delete <tag-name>
24
25# Checkout a tag
26git checkout <tag-name>

Submodules

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1# Add a submodule
2git submodule add <repository-url> <path>
3
4# Initialize submodules
5git submodule init
6
7# Update submodules
8git submodule update
9
10# Clone repository with submodules
11git clone --recurse-submodules <repository-url>
12
13# Update all submodules to latest
14git submodule update --remote

Searching

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1# Search for text in tracked files
2git grep "search term"
3
4# Search in specific file types
5git grep "search term" -- "*.js"
6
7# Search and show line numbers
8git grep -n "search term"
9
10# Search in specific commit
11git grep "search term" <commit-hash>

GitHub Authentication Setup

Setting up authentication with GitHub is essential for pushing and pulling code. Here are the two main methods: HTTPS with Personal Access Token (PAT) and SSH.

Method 1: HTTPS with Personal Access Token (Recommended for Beginners)

Step 1: Generate a Personal Access Token

1. Log in to GitHub and go to Settings → Developer settings → Personal access tokens → Tokens (classic)
2. Click "Generate new token" → "Generate new token (classic)"
3. Give your token a descriptive name
4. Set expiration (recommended: 90 days or custom)
5. Select scopes (minimum required:
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   repo
   for full repository access)
6. Click "Generate token"
7. IMPORTANT: Copy the token immediately - you won't be able to see it again!

Step 2: Use the Token for Authentication

When Git prompts for credentials:

• Username: Your GitHub username
• Password: Your Personal Access Token (not your GitHub password)

Step 3: Cache Your Credentials (Optional but Recommended)

To avoid entering credentials repeatedly:

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1# Cache credentials for 1 hour (3600 seconds)
2git config --global credential.helper 'cache --timeout=3600'
3
4# Cache credentials for 1 day (86400 seconds)
5git config --global credential.helper 'cache --timeout=86400'
6
7# For Linux: Use the credential store (stores permanently)
8git config --global credential.helper store
9
10# For macOS: Use the keychain
11git config --global credential.helper osxkeychain

First-time Push with Token

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1# Add remote repository
2git remote add origin https://github.com/username/repository.git
3
4# Push to GitHub (you'll be prompted for username and token)
5git push -u origin main

Method 2: SSH Authentication (Recommended for Regular Users)

SSH is more secure and convenient for frequent GitHub users as it doesn't require entering credentials.

Step 1: Check for Existing SSH Keys

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1# List existing SSH keys
2ls -al ~/.ssh
3
4# Look for files named id_rsa.pub, id_ed25519.pub, or similar

Step 2: Generate a New SSH Key

If you don't have an SSH key or want a new one:

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1# Generate an ED25519 SSH key (modern and secure)
2ssh-keygen -t ed25519 -C "your.email@example.com"
3
4# If your system doesn't support ED25519, use RSA
5ssh-keygen -t rsa -b 4096 -C "your.email@example.com"

When prompted:

• Press Enter to accept default file location (
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  ~/.ssh/id_ed25519
  )
• Enter a secure passphrase (optional but recommended)
• Confirm the passphrase

Step 3: Add SSH Key to the SSH Agent

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1# Start the SSH agent in the background
2eval "$(ssh-agent -s)"
3
4# Add your SSH private key to the agent
5ssh-add ~/.ssh/id_ed25519
6
7# If you used RSA instead
8ssh-add ~/.ssh/id_rsa

Step 4: Add SSH Key to Your GitHub Account

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1# Copy the SSH public key to clipboard
2# For Linux with xclip:
3sudo apt-get install xclip
4xclip -sel clip < ~/.ssh/id_ed25519.pub
5
6# Or display and copy manually:
7cat ~/.ssh/id_ed25519.pub

Then on GitHub:

1. Go to Settings → SSH and GPG keys
2. Click "New SSH key"
3. Give it a title (e.g., "My Linux Laptop")
4. Paste your public key
5. Click "Add SSH key"

Step 5: Test SSH Connection

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1# Test your SSH connection to GitHub
2ssh -T git@github.com
3
4# You should see a success message like:
5# Hi username! You've successfully authenticated, but GitHub does not provide shell access.

Step 6: Use SSH URLs for Git Operations

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1# Clone a repository using SSH
2git clone git@github.com:username/repository.git
3
4# Change existing remote from HTTPS to SSH
5git remote set-url origin git@github.com:username/repository.git
6
7# Verify the remote URL
8git remote -v

Switching Between HTTPS and SSH

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1# Check current remote URL
2git remote -v
3
4# Change from HTTPS to SSH
5git remote set-url origin git@github.com:username/repository.git
6
7# Change from SSH to HTTPS
8git remote set-url origin https://github.com/username/repository.git

Troubleshooting Authentication

HTTPS Issues

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1# If credentials are cached incorrectly
2git credential-cache exit
3
4# Or remove stored credentials (Linux)
5rm ~/.git-credentials
6
7# Test connection
8git ls-remote https://github.com/username/repository.git

SSH Issues

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1# Verify SSH key is added to agent
2ssh-add -l
3
4# Test SSH connection with verbose output
5ssh -vT git@github.com
6
7# Check SSH config
8cat ~/.ssh/config
9
10# Verify public key matches what's on GitHub
11cat ~/.ssh/id_ed25519.pub

Common Errors

"Permission denied (publickey)"

• Your SSH key isn't added to GitHub or the SSH agent
• Verify with
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  ssh-add -l
  and check GitHub SSH settings

"Support for password authentication was removed"

• GitHub no longer accepts passwords for Git operations
• Use a Personal Access Token or switch to SSH

"Could not resolve host"

• Check your internet connection
• Verify the repository URL is correct

Useful Tips & Tricks

Aliases

Create shortcuts for commonly used commands:

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1# Set up common aliases
2git config --global alias.st status
3git config --global alias.co checkout
4git config --global alias.br branch
5git config --global alias.ci commit
6git config --global alias.unstage 'reset HEAD --'
7git config --global alias.last 'log -1 HEAD'
8git config --global alias.visual 'log --graph --oneline --all'
9
10# Now you can use:
11git st          # instead of git status
12git co main     # instead of git checkout main
13git br          # instead of git branch
14git visual      # for a nice graph visualization

Ignoring Files

Create a

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1# Create .gitignore
2touch .gitignore
3
4# Add patterns (one per line)
5*.log
6*.tmp
7node_modules/
8.env
9.DS_Store
10__pycache__/
11*.pyc

Global gitignore:

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1# Create global gitignore
2git config --global core.excludesfile ~/.gitignore_global
3
4# Add common patterns
5echo ".DS_Store" >> ~/.gitignore_global
6echo "*.swp" >> ~/.gitignore_global

Viewing File from Another Branch

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1# View file content from another branch without switching
2git show <branch-name>:<file-path>
3
4# Save it to a file
5git show <branch-name>:<file-path> > temp_file.txt

Finding Bugs with Bisect

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1# Start bisect session
2git bisect start
3
4# Mark current commit as bad
5git bisect bad
6
7# Mark a known good commit
8git bisect good <commit-hash>
9
10# Git will checkout a commit in between - test it
11# Then mark it as good or bad
12git bisect good  # or git bisect bad
13
14# Repeat until Git finds the problematic commit
15
16# End bisect session
17git bisect reset

Useful Git Commands Combinations

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1# Show all commits in current branch not in main
2git log main..HEAD
3
4# Show files changed in last commit
5git diff-tree --no-commit-id --name-only -r HEAD
6
7# List all files ever committed
8git log --pretty=format: --name-only --diff-filter=A | sort -u
9
10# Count commits by author
11git shortlog -sn
12
13# Prune deleted remote branches
14git remote prune origin
15
16# Show commit count for each contributor
17git shortlog -sn --all

Best Practices

Commit Messages

• Use present tense ("Add feature" not "Added feature")
• Keep first line under 50 characters
• Add detailed description after a blank line if needed
• Reference issue numbers when applicable

Good commit message example:

CODE
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1Add user authentication feature
2
3- Implement JWT token generation
4- Add login and registration endpoints
5- Create middleware for protected routes
6- Update documentation
7
8Fixes #123

Branching Strategy

• Keep
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  main
  or
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  master
  branch stable and deployable
• Create feature branches for new work:
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  feature/user-auth
• Create hotfix branches for urgent fixes:
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  hotfix/login-bug
• Delete branches after merging
• Keep branches short-lived

General Tips

• Commit often, push regularly
• Pull before you push
• Write descriptive commit messages
• Review changes before committing (
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  git diff
  )
• Use
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  .gitignore
  for files that shouldn't be tracked
• Don't commit sensitive information (passwords, API keys)
• Keep commits focused on a single change
• Use branches for experimentation

Quick Reference Card

Essential Commands

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1# Setup
2git init                          # Initialize repository
3git clone <url>                   # Clone repository
4
5# Daily workflow
6git status                        # Check status
7git add <file>                    # Stage file
8git commit -m "message"           # Commit changes
9git push                          # Push to remote
10git pull                          # Pull from remote
11
12# Branching
13git branch <name>                 # Create branch
14git checkout <name>               # Switch branch
15git merge <name>                  # Merge branch
16
17# History
18git log                           # View history
19git diff                          # View changes
20
21# Undo
22git restore <file>                # Discard changes
23git reset HEAD~1                  # Undo last commit
24git revert <commit>               # Revert commit

Conclusion

This cheatsheet covers the most essential Git commands for daily development work and complete GitHub authentication setup. Bookmark this page for quick reference, and don't hesitate to explore the official Git documentation for more advanced features.

Remember: Git is a powerful tool, and the best way to learn is by using it regularly. Start with the basics, and gradually incorporate more advanced commands as you become comfortable.

Happy coding! 🚀

Last updated: January 2026

Additional Resources

• Official Git Documentation
• GitHub Docs
• GitHub Skills
• Interactive Git Tutorial
• Git Cheat Sheet PDF
• Git Cheat Sheet PDF