Bash argument parser as specified by https://medium.com/@Drew_Stokes/bash-argument-parsing-54f3b81a6a8f

bashargparse.sh

# parse args
PARAMS=""
while (( "$#" )); do
  case "$1" in
    -t|--telegraf-conf-dir)
      telegraf_conf_install_dir="$2"
      shift 2
      ;;
	-h|--help)
	  echo "usage: $0 [<flags>]"
	  echo "Installs app onto a centos system"
	  echo ""
	  echo "Flags:"
	  echo '  -h, --help                      Show this help and exit'
	  echo '  -t, --telegraf-conf-dir "path"  Set install directory of telegraf config. Default is /etc/telegraf/telegraf.d'
	  echo '      --                          Flag end marker; no flags after this will be parsed'
	  exit 0
	  ;;
    --) # end argument parsing
      shift
      break
      ;;
    -*|--*=) # unsupported flags
      echo "Error: Unsupported flag $1" >&2
	  echo "Invoke with -h or --help for help" >&2
      exit 1
      ;;
    *) # preserve positional arguments
      PARAMS="$PARAMS $1"
      shift
      ;;
  esac
done
# set positional arguments in their proper place
eval set -- "$PARAMS"