#!/bin/sh
set -e
[ $# -ge 1 ] || {
	echo "Usage: uchroot ROOT [CMD] [ARG].." >&2
	exit 1
}

if [ "$(id -u)" != "0" ]; then
	exec uroot "$0" "$@"
fi
###############################################################

ROOT="$1"
shift
[ -d "$ROOT" ] || {
	echo "There is no such directory: $ROOT" >&2
	exit 1
}
[ -d "$ROOT/proc" -a -d "$ROOT/dev" -a -d "$ROOT/sys" ] || {
	echo "Root seems to not contain valid rootfs: $ROOT" >&2
	exit 1
}


mount -t proc none "$ROOT/proc"
mount --rbind /dev "$ROOT/dev"
mount --rbind /sys "$ROOT/sys"
cp -f /etc/resolv.conf "$ROOT/etc/resolv.conf"

if [ $# -lt 1 ]; then
	set "/bin/sh"
fi
exec chroot "$ROOT" "$@"