Appendix B — .gitignore Patterns

How .gitignore Works

Each line in .gitignore is a pattern. Git ignores matching files.

# This is a comment
*.log           # Ignore all .log files
!important.log  # But NOT this one
/build          # Ignore build/ in root only
build/          # Ignore any directory named build
**/temp         # Ignore temp anywhere in the tree
doc/**/*.pdf    # Ignore PDFs in doc/ subdirectories

Pattern Syntax

Pattern            Matches
───────────────────────────────────────────
*.ext              Any file with that extension
dir/               A directory (and its contents)
/dir               Only in the repo root
**/pattern         At any depth
pattern/**         Everything inside pattern/
!pattern           Negate (un-ignore) a previous rule
?                  Any single character
[abc]              Any character in the set
[0-9]              Any digit

Common .gitignore Templates

Node.js

node_modules/
dist/
build/
.env
.env.local
*.log
npm-debug.log*
.DS_Store
coverage/

Python

__pycache__/
*.py[cod]
*.egg-info/
dist/
build/
.venv/
venv/
.env
*.egg
.pytest_cache/
.mypy_cache/

Java

*.class
*.jar
*.war
target/
.gradle/
build/
.idea/
*.iml

Go

bin/
vendor/
*.exe
*.test
*.out

Rust

target/
Cargo.lock  # only for libraries, keep for binaries

General / IDE

# macOS
.DS_Store
.AppleDouble
.LSOverride

# Windows
Thumbs.db
desktop.ini

# Linux
*~
.nfs*

# IDEs
.idea/
.vscode/
*.swp
*.swo
*~
.project
.classpath
.settings/

# Environment
.env
.env.local
.env.*.local

Global .gitignore

Set a global ignore file for patterns that apply to all your repos:

git config --global core.excludesfile ~/.gitignore_global

# ~/.gitignore_global
.DS_Store
Thumbs.db
*.swp
.idea/
.vscode/

Ignoring Already-Tracked Files

.gitignore only affects untracked files. To ignore a file that's already tracked:

git rm --cached filename
echo "filename" >> .gitignore
git commit -m "Stop tracking filename"

Debugging .gitignore

Example: Check why a file is ignored

git check-ignore -v path/to/file

.gitignore:3:*.log    debug.log

This tells you which rule in which file is causing the ignore.

Resources

The github/gitignore repository has comprehensive .gitignore templates for virtually every language and framework.