#!/usr/bin/env bash
# 2018 Luke Shumaker
{
	set -euE
	image=$1
	src=$(realpath -ms -- "$2")
	dst=$3

	mountpoint=$(mktemp -dt -- "${0##*/}.XXXXXXXXXX")
	trap "rmdir -- ${mountpoint@Q}" EXIT

	sudo unshare --mount sh -c "mount --make-rslave / && mount ${image@Q} ${mountpoint@Q} && cp -aT -- ${mountpoint@Q}/${src@Q} ${dst@Q}"
}