Git Configuration

Q: What is the difference between --global, local, and --system Git config?

--global applies to all repos for the current user (~/.gitconfig) Local (no flag) applies to the current repo only (.git/config) --system applies to all users on the machine (rarely used) Local settings override global, which overrides system

Q: Why is my .gitignore not ignoring a file I just added to it?

.gitignore only prevents untracked files from being staged If a file is already tracked (committed), you must untrack it first:

Q: How do I set up Git aliases for common commands?

Then use git s, git lg, git undo as shortcuts

Q: What does pull.rebase true do, and should I enable it?

It makes git pull automatically rebase instead of merge This avoids noisy merge commits when pulling updates on a feature branch Recommended for most workflows; set with git config --global pull.rebase true

Q: Gotcha: I am using the wrong email in commits on a work repo. How do I fix it?

This sets the email for the current repo only (no --global) Already-pushed commits with the wrong email cannot be changed without rewriting history

Q: How do I set up SSH keys for GitHub?

Generate a key: ssh-keygen -t ed25519 -C "you@example.com" Add it to the agent: ssh-add ~/.ssh/id_ed25519 Copy the public key and add it to GitHub under Settings > SSH and GPG keys Test with: ssh -T git@github.com

Q: What is rerere and when should I enable it?

rerere stands for "reuse recorded resolution" It remembers how you resolved a conflict and auto-applies it next time Enable with git config --global rerere.enabled true Especially useful when rebasing frequently

Q: How do I set up a pre-commit hook to run lint and type checks?

Pair with a lint-staged config in package.json to run checks only on staged files

Q: Gotcha: My Git hooks are not running. What should I check?

Ensure the hook file has execute permissions: chmod +x .husky/pre-commit With Husky v9+, confirm the .husky/ directory is properly initialized Check that prepare script exists in package.json: "prepare": "husky"

Set up Git for a productive workflow - identity, aliases, defaults, and .gitignore patterns for Next.js projects.

Recipe

Quick-reference recipe card - copy-paste ready.

# Set identity
git config --global user.name "Your Name"
git config --global user.email "you@example.com"
 
# Set default branch name
git config --global init.defaultBranch main
 
# Use rebase on pull by default
git config pull.rebase true
 
# Enable rerere (reuse recorded resolution)
git config --global rerere.enabled true
 
# Set VS Code as editor
git config --global core.editor "code --wait"
 
# View all config
git config --list --show-origin

When to reach for this: When setting up a new machine, onboarding to a project, or streamlining repetitive Git operations.

Working Example

Recommended `.gitignore` for Next.js

# Dependencies
node_modules/
.pnp/
.pnp.js
 
# Build output
.next/
out/
build/
dist/
 
# Environment files
.env
.env.local
.env.development.local
.env.test.local
.env.production.local
 
# IDE
.vscode/settings.json
.idea/
*.swp
*.swo
.DS_Store
 
# Debug
npm-debug.log*
yarn-debug.log*
yarn-error.log*
 
# TypeScript
*.tsbuildinfo
next-env.d.ts
 
# Vercel
.vercel
 
# Testing
coverage/
playwright-report/
test-results/
 
# Misc
*.pem
.turbo

What this demonstrates:

Separate sections for dependencies, build output, secrets, IDE files, and tooling
.env files are always ignored - secrets should never be committed
next-env.d.ts is auto-generated and should be ignored

Deep Dive

Useful Git Aliases

# Short status
git config --global alias.s "status -sb"
 
# Pretty log
git config --global alias.lg "log --oneline --graph --all --decorate"
 
# Undo last commit (keep changes staged)
git config --global alias.undo "reset --soft HEAD~1"
 
# Show what you did today
git config --global alias.today "log --since='midnight' --oneline --author='Your Name'"
 
# List aliases
git config --global alias.aliases "config --get-regexp ^alias"
 
# Amend without editing message
git config --global alias.amend "commit --amend --no-edit"
 
# Quick diff of staged changes
git config --global alias.staged "diff --cached"

Usage after setup:

git s            # short status
git lg           # pretty log graph
git undo         # undo last commit
git today        # today's commits
git amend        # amend last commit silently
git staged       # diff of staged changes

Global vs Local Config

# Global (applies to all repos) - stored in ~/.gitconfig
git config --global user.name "Your Name"
 
# Local (applies to this repo only) - stored in .git/config
git config user.email "work@company.com"
 
# System (applies to all users) - rarely used
git config --system core.autocrlf true
 
# Check where a config value comes from
git config --show-origin user.email

Useful Global Defaults

# Auto-correct typos (runs after 1 second)
git config --global help.autocorrect 10
 
# Colorize output
git config --global color.ui auto
 
# Set default merge strategy
git config --global merge.conflictstyle diff3
 
# Sign commits with GPG
git config --global commit.gpgsign true
git config --global user.signingkey YOUR_GPG_KEY_ID
 
# Cache credentials for 1 hour
git config --global credential.helper 'cache --timeout=3600'
 
# macOS keychain
git config --global credential.helper osxkeychain

SSH Key Setup for GitHub

# Generate a new SSH key
ssh-keygen -t ed25519 -C "you@example.com"
 
# Start the SSH agent
eval "$(ssh-agent -s)"
 
# Add key to agent
ssh-add ~/.ssh/id_ed25519
 
# Copy public key to clipboard (macOS)
pbcopy < ~/.ssh/id_ed25519.pub
# Then add to GitHub: Settings > SSH and GPG keys > New SSH key
 
# Test the connection
ssh -T git@github.com
# "Hi username! You've successfully authenticated"

Hooks

Git hooks run scripts automatically at key points in the Git workflow.

# Common hooks (in .git/hooks/ or managed by Husky)
pre-commit     # Runs before each commit - lint, format, type-check
commit-msg     # Validate commit message format
pre-push       # Runs before push - run tests
post-merge     # Runs after merge - reinstall dependencies

With Husky (recommended for team projects):

npx husky init
 
# Add a pre-commit hook
echo "npx lint-staged" > .husky/pre-commit

Gotchas

Things that will bite you. Each gotcha includes what goes wrong, why it happens, and the fix.

Wrong email in commits - Using a personal email on a work repo (or vice versa). Fix: Set local config per repo: git config user.email "work@company.com".
.gitignore not working on tracked files - Adding a file to .gitignore after it's already committed doesn't stop tracking it. Fix: git rm --cached .env to untrack it, then commit.
Line ending issues (CRLF/LF) - Windows and macOS/Linux use different line endings, causing noisy diffs. Fix: Add a .gitattributes file: * text=auto and *.tsx text eol=lf.
Hooks not running - Git hooks need execute permissions. Fix: chmod +x .husky/pre-commit. With Husky v9+, ensure the .husky/ directory is set up correctly.

Alternatives

Other ways to solve the same problem - and when each is the better choice.

Alternative	Use When	Don't Use When
`.gitattributes`	Enforcing line endings and diff behavior per file type	Simple single-platform projects
Husky + lint-staged	Team projects needing consistent pre-commit checks	Solo projects where you trust your own discipline
`direnv`	Per-directory environment config beyond Git	Git-only configuration needs

FAQs

What is the difference between `--global`, local, and `--system` Git config?

--global applies to all repos for the current user (~/.gitconfig)
Local (no flag) applies to the current repo only (.git/config)
--system applies to all users on the machine (rarely used)
Local settings override global, which overrides system

How do I check where a specific config value comes from?

git config --show-origin user.email

Shows the file path and the value, so you know if it is global or local

Why is my `.gitignore` not ignoring a file I just added to it?

.gitignore only prevents untracked files from being staged
If a file is already tracked (committed), you must untrack it first:

git rm --cached .env
git commit -m "chore: untrack .env"

How do I set up Git aliases for common commands?

git config --global alias.s "status -sb"
git config --global alias.lg "log --oneline --graph --all"
git config --global alias.undo "reset --soft HEAD~1"

Then use git s, git lg, git undo as shortcuts

What does `pull.rebase true` do, and should I enable it?

It makes git pull automatically rebase instead of merge
This avoids noisy merge commits when pulling updates on a feature branch
Recommended for most workflows; set with git config --global pull.rebase true

Gotcha: I am using the wrong email in commits on a work repo. How do I fix it?

git config user.email "work@company.com"

This sets the email for the current repo only (no --global)
Already-pushed commits with the wrong email cannot be changed without rewriting history

How do I set up SSH keys for GitHub?

Generate a key: ssh-keygen -t ed25519 -C "you@example.com"
Add it to the agent: ssh-add ~/.ssh/id_ed25519
Copy the public key and add it to GitHub under Settings > SSH and GPG keys
Test with: ssh -T git@github.com

What is `rerere` and when should I enable it?

rerere stands for "reuse recorded resolution"
It remembers how you resolved a conflict and auto-applies it next time
Enable with git config --global rerere.enabled true
Especially useful when rebasing frequently

How do I set up a pre-commit hook to run lint and type checks?

npx husky init
echo "npx lint-staged" > .husky/pre-commit

Pair with a lint-staged config in package.json to run checks only on staged files

Gotcha: My Git hooks are not running. What should I check?

Ensure the hook file has execute permissions: chmod +x .husky/pre-commit
With Husky v9+, confirm the .husky/ directory is properly initialized
Check that prepare script exists in package.json: "prepare": "husky"

In a TypeScript project, which files should go in `.gitignore`?

node_modules/, .next/, out/, dist/, build/ (dependencies and build output)
.env, .env.local, .env.*.local (secrets)
*.tsbuildinfo, next-env.d.ts (auto-generated TypeScript files)
coverage/, playwright-report/ (test output)

How do I handle CRLF vs LF line ending issues across platforms?

Add a .gitattributes file at the repo root:

* text=auto
*.tsx text eol=lf
*.ts text eol=lf

This normalizes line endings on commit regardless of the developer's OS

Essential Git Commands - Core Git operations for daily use
Git Utilities - Stash, bisect, cherry-pick, and other power tools
GitHub CLI - Manage PRs, issues, and releases from the terminal
Linting & Formatting - Set up Husky and lint-staged

Recipe

Quick-reference recipe card - copy-paste ready.

# Set identity
git config --global user.name "Your Name"
git config --global user.email "you@example.com"
 
# Set default branch name
git config --global init.defaultBranch main
 
# Use rebase on pull by default
git config pull.rebase true
 
# Enable rerere (reuse recorded resolution)
git config --global rerere.enabled true
 
# Set VS Code as editor
git config --global core.editor "code --wait"
 
# View all config
git config --list --show-origin

When to reach for this: When setting up a new machine, onboarding to a project, or streamlining repetitive Git operations.

Working Example

Recommended `.gitignore` for Next.js

# Dependencies
node_modules/
.pnp/
.pnp.js
 
# Build output
.next/
out/
build/
dist/
 
# Environment files
.env
.env.local
.env.development.local
.env.test.local
.env.production.local
 
# IDE
.vscode/settings.json
.idea/
*.swp
*.swo
.DS_Store
 
# Debug
npm-debug.log*
yarn-debug.log*
yarn-error.log*
 
# TypeScript
*.tsbuildinfo
next-env.d.ts
 
# Vercel
.vercel
 
# Testing
coverage/
playwright-report/
test-results/
 
# Misc
*.pem
.turbo

What this demonstrates:

Separate sections for dependencies, build output, secrets, IDE files, and tooling
.env files are always ignored - secrets should never be committed
next-env.d.ts is auto-generated and should be ignored

Deep Dive

Useful Git Aliases

# Short status
git config --global alias.s "status -sb"
 
# Pretty log
git config --global alias.lg "log --oneline --graph --all --decorate"
 
# Undo last commit (keep changes staged)
git config --global alias.undo "reset --soft HEAD~1"
 
# Show what you did today
git config --global alias.today "log --since='midnight' --oneline --author='Your Name'"
 
# List aliases
git config --global alias.aliases "config --get-regexp ^alias"
 
# Amend without editing message
git config --global alias.amend "commit --amend --no-edit"
 
# Quick diff of staged changes
git config --global alias.staged "diff --cached"

Usage after setup:

git s            # short status
git lg           # pretty log graph
git undo         # undo last commit
git today        # today's commits
git amend        # amend last commit silently
git staged       # diff of staged changes

Global vs Local Config

# Global (applies to all repos) - stored in ~/.gitconfig
git config --global user.name "Your Name"
 
# Local (applies to this repo only) - stored in .git/config
git config user.email "work@company.com"
 
# System (applies to all users) - rarely used
git config --system core.autocrlf true
 
# Check where a config value comes from
git config --show-origin user.email

Useful Global Defaults

# Auto-correct typos (runs after 1 second)
git config --global help.autocorrect 10
 
# Colorize output
git config --global color.ui auto
 
# Set default merge strategy
git config --global merge.conflictstyle diff3
 
# Sign commits with GPG
git config --global commit.gpgsign true
git config --global user.signingkey YOUR_GPG_KEY_ID
 
# Cache credentials for 1 hour
git config --global credential.helper 'cache --timeout=3600'
 
# macOS keychain
git config --global credential.helper osxkeychain

SSH Key Setup for GitHub

# Generate a new SSH key
ssh-keygen -t ed25519 -C "you@example.com"
 
# Start the SSH agent
eval "$(ssh-agent -s)"
 
# Add key to agent
ssh-add ~/.ssh/id_ed25519
 
# Copy public key to clipboard (macOS)
pbcopy < ~/.ssh/id_ed25519.pub
# Then add to GitHub: Settings > SSH and GPG keys > New SSH key
 
# Test the connection
ssh -T git@github.com
# "Hi username! You've successfully authenticated"

Hooks

Git hooks run scripts automatically at key points in the Git workflow.

# Common hooks (in .git/hooks/ or managed by Husky)
pre-commit     # Runs before each commit - lint, format, type-check
commit-msg     # Validate commit message format
pre-push       # Runs before push - run tests
post-merge     # Runs after merge - reinstall dependencies

With Husky (recommended for team projects):

npx husky init
 
# Add a pre-commit hook
echo "npx lint-staged" > .husky/pre-commit

Gotchas

Things that will bite you. Each gotcha includes what goes wrong, why it happens, and the fix.

Wrong email in commits - Using a personal email on a work repo (or vice versa). Fix: Set local config per repo: git config user.email "work@company.com".
.gitignore not working on tracked files - Adding a file to .gitignore after it's already committed doesn't stop tracking it. Fix: git rm --cached .env to untrack it, then commit.
Line ending issues (CRLF/LF) - Windows and macOS/Linux use different line endings, causing noisy diffs. Fix: Add a .gitattributes file: * text=auto and *.tsx text eol=lf.
Hooks not running - Git hooks need execute permissions. Fix: chmod +x .husky/pre-commit. With Husky v9+, ensure the .husky/ directory is set up correctly.

Alternatives

Other ways to solve the same problem - and when each is the better choice.

Alternative	Use When	Don't Use When
`.gitattributes`	Enforcing line endings and diff behavior per file type	Simple single-platform projects
Husky + lint-staged	Team projects needing consistent pre-commit checks	Solo projects where you trust your own discipline
`direnv`	Per-directory environment config beyond Git	Git-only configuration needs

FAQs

What is the difference between `--global`, local, and `--system` Git config?

--global applies to all repos for the current user (~/.gitconfig)
Local (no flag) applies to the current repo only (.git/config)
--system applies to all users on the machine (rarely used)
Local settings override global, which overrides system

How do I check where a specific config value comes from?

git config --show-origin user.email

Shows the file path and the value, so you know if it is global or local

Why is my `.gitignore` not ignoring a file I just added to it?

.gitignore only prevents untracked files from being staged
If a file is already tracked (committed), you must untrack it first:

git rm --cached .env
git commit -m "chore: untrack .env"

How do I set up Git aliases for common commands?

git config --global alias.s "status -sb"
git config --global alias.lg "log --oneline --graph --all"
git config --global alias.undo "reset --soft HEAD~1"

Then use git s, git lg, git undo as shortcuts

What does `pull.rebase true` do, and should I enable it?

It makes git pull automatically rebase instead of merge
This avoids noisy merge commits when pulling updates on a feature branch
Recommended for most workflows; set with git config --global pull.rebase true

Gotcha: I am using the wrong email in commits on a work repo. How do I fix it?

git config user.email "work@company.com"

This sets the email for the current repo only (no --global)
Already-pushed commits with the wrong email cannot be changed without rewriting history

How do I set up SSH keys for GitHub?

Generate a key: ssh-keygen -t ed25519 -C "you@example.com"
Add it to the agent: ssh-add ~/.ssh/id_ed25519
Copy the public key and add it to GitHub under Settings > SSH and GPG keys
Test with: ssh -T git@github.com

What is `rerere` and when should I enable it?

rerere stands for "reuse recorded resolution"
It remembers how you resolved a conflict and auto-applies it next time
Enable with git config --global rerere.enabled true
Especially useful when rebasing frequently

How do I set up a pre-commit hook to run lint and type checks?

npx husky init
echo "npx lint-staged" > .husky/pre-commit

Pair with a lint-staged config in package.json to run checks only on staged files

Gotcha: My Git hooks are not running. What should I check?

Ensure the hook file has execute permissions: chmod +x .husky/pre-commit
With Husky v9+, confirm the .husky/ directory is properly initialized
Check that prepare script exists in package.json: "prepare": "husky"

In a TypeScript project, which files should go in `.gitignore`?

node_modules/, .next/, out/, dist/, build/ (dependencies and build output)
.env, .env.local, .env.*.local (secrets)
*.tsbuildinfo, next-env.d.ts (auto-generated TypeScript files)
coverage/, playwright-report/ (test output)

How do I handle CRLF vs LF line ending issues across platforms?

Add a .gitattributes file at the repo root:

* text=auto
*.tsx text eol=lf
*.ts text eol=lf

This normalizes line endings on commit regardless of the developer's OS

Essential Git Commands - Core Git operations for daily use
Git Utilities - Stash, bisect, cherry-pick, and other power tools
GitHub CLI - Manage PRs, issues, and releases from the terminal
Linting & Formatting - Set up Husky and lint-staged

Git Configuration

Search Documentation

Git Configuration