Introduction
# 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/