About Shell Script Linter

Check shell scripts for common issues and bad practices. Part of the DevTools Surf developer suite. Browse more tools in the Developer Utilities collection.

Use Cases

• Validate deployment scripts before running in production
• Catch quoting errors that cause silent data corruption
• Ensure shell scripts are POSIX-compatible across platforms
• Review CI/CD pipeline scripts for reliability issues

Tips

• Paste a shell script to check for common pitfalls
• Catch unquoted variables that cause word splitting bugs
• Identify non-portable bashisms in supposedly POSIX scripts

Fun Facts

• ShellCheck, the most popular shell linter, was created by Vidar Holen in 2012 and has over 100 unique checks for bash, sh, dash, and ksh.
• The Bourne shell (sh) was written by Stephen Bourne at Bell Labs in 1979; Bash (Bourne Again Shell) was created by Brian Fox for GNU in 1989.
• Unquoted variables in shell scripts are the single most common source of bugs, responsible for path injection, word splitting, and glob expansion issues.

FAQ

What rules does it check?

ShellCheck's common rules: unquoted variables (word splitting), `[ "$x" = y ]` vs `[[ ]]`, backticks vs $(), `ls | grep` antipattern. The usual shell footguns.

Which shell dialects?

Bash, sh (POSIX), and dash. Bashisms in POSIX-targeted scripts get flagged; POSIX-strict features in bash scripts might be called overly-cautious.

Does it fix issues?

Reports only. Many shell fixes are subjective (quoting style, $(()) vs `expr`) so the tool suggests without auto-applying.

Is it as comprehensive as ShellCheck?

Covers ~80% of ShellCheck's rules. For CI pipelines use ShellCheck directly — this tool is for quick one-off checks in the browser.