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 [s]hell dialect (overrides the shebang at the top of the script):

`shellcheck --shell {{sh|bash|dash|ksh}} {{path/to/script.sh}}`

- Ignor[e] one or more error types:

`shellcheck --exclude {{SC1009,SC1073,...}} {{path/to/script.sh}}`

- Also check any sourced shell scripts:

`shellcheck --check-sourced {{path/to/script.sh}}`

- Display output in the specified [f]ormat (defaults to `tty`):

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

- Enable one or more [o]ptional checks:

`shellcheck --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 [S]everity to consider (defaults to `style`):

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