Shell command line arguments.

shell.arguments.sh

#!/usr/bin/env bash

prog=$(basename ${0})

# Defaults
verbose=0
env="staging"

function help() {
    printf "Usage: %s [-h/--help] [-e/--env <env>] <url>\n" "$prog"
    exit 0
}

# Parse Options
while :; do
    case $1 in
        -h|-\?|--help)
            help
            exit
            ;;
        -e|--env)
            if [ -n "$2" ]; then
                env=$2
                shift 2
                continue
            else
                printf "ERROR: -e/--env requires a non-empty option argument.\n" >&2
                exit 1
            fi
            ;;
        -v|--verbose)
            verbose=$((verbose + 1))
        ;;
        --)
            shift
            break
            ;;
        -?*)
            printf "WARN: Unknown option (ignored): %s\n" "$1" >&2
            ;;
        *)
            break
    esac

    command shift
done


if (( $verbose > 0 )); then
    echo "env=${env}"
    echo "url='${@}'"
fi