bash

parse_args.sh

function get_help () {
cat << EOF

Help

EOF
}

function handle_kwarg () {
  if [ -n "$2" ] && [ ${2:0:1} != "-" ]; then
    echo $2
  else
    echo "Error: Argument for $1 is missing" >&2
    exit 1
  fi
}

POSITIONAL=()

while [[ $# -gt 0 ]]; do
  case "$1" in
      --help)
        get_help
        exit 0 ;;
      # parse flags, bool parameters
      -f|--flag)
        MY_FLAG=0 
        shift ;;
      # parse parameters with values
      -o|--output)
        TEST=$(handle_kwarg $1 $2)
        shift 2 ;;
      -*|--*) 
        echo "Error: Unsupported flag $1" >&2
        exit 1 ;;
      *)
        POSITIONAL+=("$1") 
        shift ;;
  esac
done

# restore positional parameters
set -- "${POSITIONAL[@]}"