Parsing CLI options in bash

options.sh

# taken from http://www.unix.com/302182212-post4.html

while true
do
  case $# in 0) break ;; esac
  case $1 in
    -d|--dir) shift; dir=$1; shift ;;
    -u|--user) shift; user=$1; shift ;;
    -a|--all) shift; all=true ;;
    -|--) shift; break;;
    -h|--help) cat <<______EOF >&2; exit 0 ;;
Syntax: $0 [ -d directory | --dir directory ] [ -u user | --user user ] | --help
______EOF
    -*) cat <<______EOF >&2; exit 2 ;;
Invalid option $1.  Try $0 --help to see available options.
______EOF
    *) break ;;
  esac
done

set -e

# other stuffs