Git Essentials

# Git Essentials

Essential Git commands for version control and collaboration.

Initial Setup

```bash # Configure user git config --global user.name "Your Name" git config --global user.email "[email protected]"

# Initialize repository git init

# Clone repository git clone https://github.com/user/repo.git git clone https://github.com/user/repo.git custom-name ```

Basic Workflow

Staging and committing ```bash # Check status git status

# Add files to staging git add file.txt git add . git add -A # All changes including deletions

# Commit changes git commit -m "Commit message"

# Add and commit in one step git commit -am "Message"

# Amend last commit git commit --amend -m "New message" git commit --amend --no-edit # Keep message ```

Viewing changes ```bash # Show unstaged changes git diff

# Show staged changes git diff --staged

# Show changes in specific file git diff file.txt

# Show changes between commits git diff commit1 commit2 ```

Branching & Merging

Branch management ```bash # List branches git branch git branch -a # Include remote branches

# Create branch git branch feature-name

# Switch branch git checkout feature-name git switch feature-name # Modern alternative

# Create and switch git checkout -b feature-name git switch -c feature-name

# Delete branch git branch -d branch-name git branch -D branch-name # Force delete

# Rename branch git branch -m old-name new-name ```

Merging ```bash # Merge branch into current git merge feature-name

# Merge with no fast-forward git merge --no-ff feature-name

# Abort merge git merge --abort

# Show merge conflicts git diff --name-only --diff-filter=U ```

Remote Operations

Managing remotes ```bash # List remotes git remote -v

# Add remote git remote add origin https://github.com/user/repo.git

# Change remote URL git remote set-url origin https://github.com/user/new-repo.git

# Remove remote git remote remove origin ```

Syncing with remote ```bash # Fetch from remote git fetch origin

# Pull changes (fetch + merge) git pull

# Pull with rebase git pull --rebase

# Push changes git push

# Push new branch git push -u origin branch-name

# Force push (careful!) git push --force-with-lease ```

History & Logs

Viewing history ```bash # Show commit history git log

# One line per commit git log --oneline

# With graph git log --graph --oneline --all

# Last N commits git log -5

# Commits by author git log --author="Name"

# Commits in date range git log --since="2 weeks ago" git log --until="2024-01-01"

# File history git log -- file.txt ```

Searching history ```bash # Search commit messages git log --grep="bug fix"

# Search code changes git log -S "function_name"

# Show who changed each line git blame file.txt

# Find commit that introduced bug git bisect start git bisect bad git bisect good commit-hash ```

Undoing Changes

Working directory ```bash # Discard changes in file git restore file.txt git checkout -- file.txt # Old way

# Discard all changes git restore . ```

Staging area ```bash # Unstage file git restore --staged file.txt git reset HEAD file.txt # Old way

# Unstage all git reset ```

Commits ```bash # Undo last commit (keep changes) git reset --soft HEAD~1

# Undo last commit (discard changes) git reset --hard HEAD~1

# Revert commit (create new commit) git revert commit-hash

# Reset to specific commit git reset --hard commit-hash ```

Stashing

```bash # Stash changes git stash

# Stash with message git stash save "Work in progress"

# List stashes git stash list

# Apply latest stash git stash apply

# Apply and remove stash git stash pop

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

# Delete stash git stash drop stash@{0}

# Clear all stashes git stash clear ```

Rebasing

```bash # Rebase current branch git rebase main

# Interactive rebase (last 3 commits) git rebase -i HEAD~3

# Continue after resolving conflicts git rebase --continue

# Skip current commit git rebase --skip

# Abort rebase git rebase --abort ```

Tags

```bash # List tags git tag

# Create lightweight tag git tag v1.0.0

# Create annotated tag git tag -a v1.0.0 -m "Version 1.0.0"

# Tag specific commit git tag v1.0.0 commit-hash

# Push tag git push origin v1.0.0

# Push all tags git push --tags

# Delete tag git tag -d v1.0.0 git push origin --delete v1.0.0 ```

Advanced Operations

Cherry-pick ```bash # Apply specific commit git cherry-pick commit-hash

# Cherry-pick without committing git cherry-pick -n commit-hash ```

Submodules ```bash # Add submodule git submodule add https://github.com/user/repo.git path/

# Initialize submodules git submodule init

# Update submodules git submodule update

# Clone with submodules git clone --recursive https://github.com/user/repo.git ```

Clean ```bash # Preview files to be deleted git clean -n

# Delete untracked files git clean -f

# Delete untracked files and directories git clean -fd

# Include ignored files git clean -fdx ```

Common Workflows

Feature branch workflow: ```bash git checkout -b feature/new-feature # Make changes git add . git commit -m "Add new feature" git push -u origin feature/new-feature # Create PR, then after merge: git checkout main git pull git branch -d feature/new-feature ```

Hotfix workflow: ```bash git checkout main git pull git checkout -b hotfix/critical-bug # Fix bug git commit -am "Fix critical bug" git push -u origin hotfix/critical-bug # After merge: git checkout main && git pull ```

Syncing fork: ```bash git remote add upstream https://github.com/original/repo.git git fetch upstream git checkout main git merge upstream/main git push origin main ```

Useful Aliases

Add to `~/.gitconfig`: ```ini [alias] st = status co = checkout br = branch ci = commit unstage = reset HEAD -- last = log -1 HEAD visual = log --graph --oneline --all amend = commit --amend --no-edit ```

Tips

• Commit often, perfect later (interactive rebase)
• Write meaningful commit messages
• Use `.gitignore` for files to exclude
• Never force push to shared branches
• Pull before starting work
• Use feature branches, not main
• Rebase feature branches before merging
• Use `--force-with-lease` instead of `--force`

Common Issues

Undo accidental commit: ```bash git reset --soft HEAD~1 ```

Recover deleted branch: ```bash git reflog git checkout -b branch-name <commit-hash> ```

Fix wrong commit message: ```bash git commit --amend -m "Correct message" ```

Resolve merge conflicts: ```bash # Edit files to resolve conflicts git add resolved-files git commit # Or git merge --continue ```

Documentation

Official docs: https://git-scm.com/doc Pro Git book: https://git-scm.com/book Visual Git guide: https://marklodato.github.io/visual-git-guide/