#!/bin/sh
set -eu

usage() {
	cat <<-'EOF'
		Usage:
		  uuid
		  uuid -h
	EOF
}

help() {
	cat <<-'EOF'

		Options:
		  -h, --help    show this message

		Generate UUID from /dev/random.
	EOF
}

for flag in "$@"; do
	case "$flag" in
		--)
			break
			;;
		--help)
			usage
			help
			exit
			;;
		*)
			;;
	esac
done

while getopts 'h' flag; do
	case "$flag" in
		h)
			usage
			help
			exit
			;;
		*)
			usage >&2
			exit 2
			;;
	esac
done
shift $((OPTIND - 1))

od -xN20 /dev/random |
	awk 'NR == 1 { OFS="-"; print $2$3,$4,$5,$6,$7$8$9; exit }'
