How to use getopts in bash

getopts.sh

#!/bin/bash
usage() {
  echo "Usage: $(basename "$0") [-v] [-f filename] [-g group] positional-param"
  exit 1
}

if [[ "$#" -lt 1 ]]; then
  usage
fi

# Prefix getops string with : to silence errors
# Option without : is just an option (-v)
# Append : to an option to accept a parameter (-f filename)
while getopts ":vf:g:" opt; do
  case $opt in
    v) echo "-v enabled";;
    f) echo "-f was passed $OPTARG";;
    g) echo "-g was passed $OPTARG";;
    ?) case $OPTARG in
        f|g) echo "-$OPTARG missing argument"; usage;;
        ?) usage;;
      esac
  esac
done
# Remove all params processed by getopts so we can use $1 like normal
shift $((OPTIND - 1))

echo "positional parameter passed is $1"