#!/bin/sh

set -e

removes () {
	if test -L "$vardir/snap-mount"; then
		rm -f -- "$vardir/snap-mount"
	elif test -d "$vardir/snap-mount"; then
		rmdir -- "$vardir/snap-mount"
	fi
	rm -f -- "$vardir/snap-device"
}

vardir="$2"

case "$#.$1" in
2.drop)
	removes
	;;
4.snap)
	removes
	ln -s -- "$3" "$vardir/snap-device"
	ln -s -- "$4" "$vardir/snap-mount"
	;;
*)
	cat >&2 <<'END'
usage: .../nosnap snap VARDIR DEV MOUNT
       .../nosnap drop VARDIR
END
	exit 1
	;;
esac