Example bash getopts

gistfile1.sh

#!/bin/bash

usage() {

cat << EOT

  usage $0 [-hgw]
        $0 -m MESSAGE

  OPTIONS
    -h show this usage
    -m show message "Hello <m option arguments>
    -g show message "Hello Git!!"
    -w show message "Hello World!!"
EOT
}

main() {
    echo "Hello $HELLOTO!!"
}

HELLOTO=`whoami`
while getopts "hgwm:" option; do
    case $option in
        g)
          HELLOTO="Git"
          ;;
        w)
          HELLOTO="World"
          ;;
        m)
          HELLOTO="$OPTARG"
          ;;
        \?)
          echo "wrong option."
          usage
          exit 1
          ;;
        h)
          usage
          exit 0
          ;;
    esac
done
shift $(($OPTIND - 1))

main