Довольно своеобразные дебаг и usage

usage() {
	echo "$0 [OPTIONS] <nas_id>""
	grep "^# usage:" $0 | sed -e 's/# usage: //g'
	echo "where OPTIONS is:"
	grep -m1 -A 1000 "^parse_params" $0 | grep -B 1000 -m1 "^}" | grep ".*|.*)$" | tr '|' '-' | tr -d ')'
	exit 1
}

parse_params() {
	debug=0
	verbose=0
	upload=0
	force=0
	while [ "$#" -gt 0 ]; do
		param="${1//-/}"
		case "$param" in
		v | verbose )
			verbose=1
			shift ;;
		u | upload )
			upload=1
			shift ;;
		f | force )
			force=1
			shift ;;
		d | debug )
			debug=1
			PS4='+ ${BASH_SOURCE##*/} $LINENO:      '
			set -x
			shift ;;
		help | h | usage )
			usage
			;;
		* )
			break
			;;
		esac
	done
	nas_id=$1
}