Automatically generate help output from function comments in bash scripts

README.md

Auto-help output for bash scripts

Use the attached help() function to automatically generate a help/usage output from function comments.

Example:

$ ./sample.sh
blondie - Call Blondie
help - Print help; use "help NAME" to show details

You may also specify commands:

$ ./sample.sh help blondie
blondie is a function
blondie ()
{
	echo 'call me, on the line, call me, call me, call me, anytime, call me'
}

sample.sh

#!/usr/bin/env bash

# Call Blondie
blondie()
{
	echo 'call me, on the line, call me, call me, call me, anytime, call me'
}

# Print help; use "help NAME" to show details
help()
{
	(( $# > 0 )) && {
		type "$@"
		return $?
	}

	local DESC=''

	while read -r
	do
		case $REPLY in
			*\(\))
				[ "$DESC" ] || continue
				echo "${REPLY%(*} - $DESC"
				DESC=
				;;
			\#\ *)
				[ "$DESC" ] && continue
				DESC=${REPLY#*#}
				;;
		esac
	done < "$0"
}

if [ "${BASH_SOURCE[0]}" == "$0" ]
then
	"${@:-help}"
fi