Bash command line arguments parse

bash_arguments.sh

#!/bin/bash

showUsage() {
  echo "Usage:
  Usage instruction..."
}

if (( ${#@} == 0 )); then
	showUsage
	exit 1
fi

while [ "$1" != "" ]; do
  case $1 in
    -f | --file )
                            shift
                            filename=$1
                            ;;
    -i | --interactive )
                            interactive=1
                            ;;
    -h | --help )
                            showUsage
                            exit 0
                            ;;
    * )
                            showUsage
                            exit 1
                            ;;
  esac
  shift
done

exit 0