#!/usr/bin/env bash

set -e
set -o pipefail

usage() {
	echo 'dir-size [-h] <DIR> [du options...]
prints the number of bytes in DIR
additional (after first) arguments are passed to du'
	exit "${1:-0}"
}

[[ "$1" == '-h' ]] && usage

DIR="$1"
if [[ -z "$DIR" ]]; then
	echo -e 'dir-size: error: Pass directory as first argument\n' >&2
	usage 1
fi
shift

if [[ ! -d "$DIR" ]]; then
	printf '%s is not a directory\n' "$DIR" >&2
	exit 1
fi

du -bcs "$@" "$DIR" | awk 'END{print $1}' || exit $?