hello-world

#!/usr/bin/env bash

prog=$0

warn() { [ $# -gt 0 ] && echo $prog: "$@" 1>&2; }
abort() { warn "$@"; exit 1; }

usage() {
  warn "$@"
  cat <<EOT
USAGE: $(basename $prog) [-h]

Prints "hello world" to stdout.

OPTIONS:
  -h              Print this and exit.
EOT
  exit;
}

while getopts "h" o; do
  case "${o}" in
    h) usage ;;
    ?) abort ;;
  esac
done
shift $((OPTIND-1))

echo hello world