tldr/pages/common/shellcheck.md

shellcheck

Statically check shell scripts for errors, usage of deprecated/insecure features, and bad practices. More information: https://github.com/koalaman/shellcheck/wiki.

• Check a shell script:

shellcheck {{path/to/script.sh}}

• Check a shell script interpreting it as the specified shell dialect (overrides the shebang at the top of the script):

shellcheck {{[-s|--shell]}} {{sh|bash|dash|ksh}} {{path/to/script.sh}}

• Ignore one or more error types:

shellcheck {{[-e|--exclude]}} {{SC1009,SC1073,...}} {{path/to/script.sh}}

• Also check any sourced shell scripts:

shellcheck {{[-a|--check-sourced]}} {{path/to/script.sh}}

• Display output in the specified format (defaults to tty):

shellcheck {{[-f|--format]}} {{tty|checkstyle|diff|gcc|json|json1|quiet}} {{path/to/script.sh}}

• Enable one or more [o]ptional checks:

shellcheck {{[-o|--enable]}} {{add-default-case,avoid-nullary-conditions,...}} {{path/to/script.sh}}

• List all available optional checks that are disabled by default:

shellcheck --list-optional

• Adjust the level of severity to consider (defaults to style):

shellcheck {{[-S|--severity]}} {{error|warning|info|style}} {{path/to/script.sh}}