GIt

The most popular version control system, for tracking changes to code.

Concepts

• Repository: Project folder
• Commit: Saved snapshot of changes
• Branch: Independent line of development
• Main branch: Holds the official project history. Usually main or master.
• Remote: Copy of repo on another machine / server
• Stash: Temporary storage for uncommitted changes
• Tag: Named reference to a specific commit
• Cherry-pick: Apply a specific commit to another branch

Initial Setup

git config --global user.name 'Madusha Prasanjith'
git config --global user.email 'hi@madusha.me'

Managing Repositories

# Initialize a new repo
git init

# Clone existing
git clone <repo-url>

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

Managing Branches

# List all branches
git branch

# Create a branch
git branch <branch-name>

# Checkout a branch
git checkout -b <branch-name> # Create + checkout branch
git checkout <branch-name> # Checkout existing branch

# Delete a branch
git branch -d <feature-name> # Delete locally (only works if branch merged)
git branch -D <feature-name> # Delete locally (force delete unmerged branch)
git push origin --delete <feature-name> # Delete remotely

Managing Changes

# List changes
git status

# Show unstaged changes
git diff

# Add a file or folder
git add <files>

# Add all changes
git add -A

Creating Commits

# Add a file or folder
git commit -m "Descriptive message"

# Add current changes to the last commit
git commit --amend

Merging Branches

Git merging combines changes from two different branches into a single branch.

Types:

1. Fast-forward merge: When target branch is behind source branch
2. Three-way merge: When both branches have diverged, requiring a merge commit

Both are handled through the same commands:

# 1. Checkout destination branch
git checkout main

# 2. Merge source branch to destination
git merge <feature-name>

Handling conflicts explained below in Handling Merge Conflicts.

Syncing with Remote

# Fetch remote branch
git fetch <remote> <branch-name>
git fetch <remote> # Fetch all remote branches

# Fetch current branch from remote and merge it with local copy
git pull <remote>

# Push to remote
git push # Push to already setup remote branch
git push -u <remote-name> <feature-name> # Setup a remote branch and push
git push <remote-name> --delete <feature-name> # Delete remote

# CAUTION
# replaces remote changes with your local changes.
# This is destructive and remove all remote changes you don't have locally!
git push --force <remote> <branch>

# A more safer force option, which will abort if there are changes in remote which you don't have locally.
git push --force-with-lease <remote> <branch>

Stashing

# Stash changes
git stash

# Apply stash
git stash pop # Apply and remove
git stash apply # Apply and keep

# List all stashes
git stash list

# Remove a specific stash
git stash drop stash@{n}

Tagging

# Create lightweight tag
git tag v1.0.0

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

# Push tag to remote
git push origin v1.0.0

# Deleting tags
git tag -d v1.0.0 # Delete local tag
git push origin --delete v1.0.0 # Delete remote tag

Undoing changes

# Remove staged file but keep changes
git reset <file>

# Revert a commit
git revert <commit>

Cherry-picking

# Cherry-pick a commit
git cherry-pick <commit-hash> # Cherry-pick and commit
git cherry-pick -n <commit-hash> # Cherry-pick and stage without committing

# Abort cherry-pick
git cherry-pick --abort