host=$1
user=$2
d=$3
shift 3
: ${ssh_args:=-oControlPath=~/.ssh/master-vnc-%r@%h:%p}
[ -n "$d" ] || {
	echo >&2 usage: `basename "$0"` host user display-number
	exit 1
}
VNC_VIA_CMD="/usr/bin/ssh $ssh_args -l $user -f -L %L:%H:%R %G sleep 20" ${vv:-xtightvncviewer} -encodings 'copyrect tight hextile zlib corre rre raw' -via $host -passwd $HOME/.vnc/passwd "$@" localhost:$d