bash getopts example

bash-getopts-example.sh

#!/bin/bash

# first colon turns getopts into silent mode
# that also sets OPTARG when errors happen
#
# options with arguments have a colon AFTER the
# option letter
# in the example, a requires an option, b no

while getopts ":a:b" opt; do
    case $opt in
        a)
            echo "a with $OPTARG"
            ;;
        b)
            echo "b was set"
            ;;
        \?)
            echo "INVALID OPTION: $OPTARG"
            ;;
        \:)
            echo "INVALID ARGUMENT: $OPTARG"
            ;;
    esac
done

shift $((OPTIND - 1))

echo "$@"