Ask HN: Unix Utility Development Conventions

  version=1.0.0

  usage() {
    cat << EOF
  USAGE: $0 {{-f|--file} <filename>}

  Some description.

  OPTIONS
    -h, --help
      Display this help.

    -v, --version
      Display version.

    -f <filepath>, --file <filepath>
      Specify input file.
  EOF
  }

  while (( $# )); do
    case "$1" in
      -h|--help)
        usage
        exit
      ;;

      -v|--version)
        printf "%s\n" "$version"
        exit
      ;;

      -f|--file)
        input_file="$2"
        shift
      ;;

      *)
        >&2 printf "Unknown option: %s\n" "$1"
        >&2 usage
        exit 1
      ;;
    esac
    shift
  done