#!/bin/bash

parse() {

    while read line; do

        [ "${line:0:1}" = '#' -o "${line:0:1}" = ';' ] && continue

        line="${line## *}"

        [ -z "$line" ] && continue

        set -- $line

        case "$1" in

            ('u')

                echo "user($2)"

                echo "group($2)"

                # TODO: user:group support

                ;;

            ('g')

                echo "group($2)"

                ;;

            ('m')

                echo "user($2)"

                echo "group($3)"

                ;;

        esac

    done

}

while read fn; do

    parse < "$fn"

done