#!/bin/sh usage() { echo nope echo opens files } case "$@" in --help) usage exit 1 ;; *.pdf) okular "$@" > /dev/null 2>&1 & ;; *.html) firefox "$@" > /dev/null 2>&1 & ;; *.mp4|*.mp3) vlc "$@" > /dev/null 2>&1 & ;; *) echo "No rule for opening this file has been specified" exit 1 ;; esac