Shell script template with long arguments

shell-script-template.sh

#!/usr/bin/env bash
set -o errexit
set -o pipefail

usage() {
echo "
    ${0##*/}

    DESCRIPTION:
        Script explanation
        
    USAGE:
        ${0##*/} [OPTION] ... [OPTION]
        
        -n | --longoption (required)
            description
        -? -h
            display this help and exit

    EXAMPLE:
        ${0##*/} -n"
}

# check for empty argument
if [[ -z "$1" ]] ; then
    usage
    exit 1
fi

# parse options
    # short options after -o
    # long options after --long
    # add : after options that require a value and shift by 2
    #   e.g. -m | --memory ) MEMORY="$2"; shift 2 ;;
    # for options that do not require a value, shift by 1
    #   e.g. -v | --verbose ) VERBOSE=true; shift ;;
    # script name after -n
    # $1 is option, $2 is the option argument
TEMP=`getopt -o vd:h --long longoption,longoption-with-argument:,help \
             -n 'programname' -- "$@"`

if [[ $? != 0 ]] ; then echo "Terminating..." >&2 ; exit 1 ; fi

eval set -- "$TEMP"

while true; do
    case "$1" in
        -v | --longoption) 
            echo v and verbose; shift;;
        -d | --longoption-with-argument) 
            echo arguement is $2; shift 2;;
        -h | --help)
            usage
            exit 2
            break;;
        --) 
            shift; break;;
        *) 
            break;;
    esac
done

# stores working directory
working_directory=$(pwd)
# stores script directory
script_directory="$(cd $(dirname $0); pwd)"

# changes to script directory
cd "$script_directory"

# check required arguments
if [[ -z "$requirement" ]] || [[ -z "$requirement" ]]; then
    usage
    exit 6
fi