#!/bin/bash
XDT=/usr/bin/xdotool
WINDOW=`$XDT getwindowfocus`
# this brings in variables WIDTH and HEIGHT
eval `xdotool getwindowgeometry --shell $WINDOW`
TX=`expr $WIDTH / 2`
TY=`expr $HEIGHT / 2`
$XDT mousemove -window $WINDOW $TX $TY