References & Tools

Official Documentation

The authoritative sources. When a guide and the manual disagree, the manual wins.

• GNU Bash Reference Manual — the complete language and builtin reference, free from the GNU project.
• Bash Reference Manual (single page) — easier to search than the split HTML.
• POSIX Shell Command Language — the standard behind /bin/sh.
• bash(1) man page — what man bash shows on your machine.

Free Books & Guides

• Greg's Wiki — BashGuide — a modern, correct, free guide (the successor to the defunct Bash Hackers Wiki).
• Greg's Wiki — BashFAQ — answers to the questions every shell programmer asks.
• Greg's Wiki — BashPitfalls — the classic mistakes, with fixes.
• Bash Guide for Beginners (TLDP) — a gentle, complete introduction.
• Advanced Bash-Scripting Guide (TLDP) — vast, though not always idiomatic; read critically.
• The Pure Bash Bible — pure-Bash replacements for external tools, free on GitHub.

Style Guides & Standards

• Google Shell Style Guide — pragmatic rules used across Google's shell code.
• ShellCheck Wiki — an explanation for every ShellCheck code.
• ShellCheck source (GitHub) — install instructions and integration list.

Tools & Linters

• ShellCheck online — paste a script and get warnings in the browser.
• explainshell — paste a command line and see each part explained.
• bats-core — Bash Automated Testing System, free and open source.
• shfmt — a shell formatter to keep style consistent.

Practice & Games

• LearnShell.org — an interactive browser tutorial you can type into.
• OverTheWire: Bandit — learn the shell by solving SSH puzzles.
• Exercism — Bash track — mentored exercises, free.
• Command Line Challenge — short tasks that test one-liners.

Sample Repositories

• awesome-bash — a curated list of frameworks, tools and resources.
• ShellCheck test suite — hundreds of small scripts showing correct and incorrect patterns.
• awesome-cli-apps — real command-line programs written in Bash and friends.
• neofetch — a large, readable, purely-Bash program to study.

How to Choose

• Learning from scratch: TLDP Beginners Guide, then Greg's BashGuide.
• Checking a specific behaviour: the GNU manual and man bash.
• Fixing a script: ShellCheck first, then BashPitfalls.
• Building a habit: the Google Shell Style Guide and a test suite with bats.
• Practising: LearnShell, then Bandit or Exercism once the basics feel solid.