wmctrl -l

xdotool getwindowgeometry --shell window_id

WINDOW=69206033
X=6
Y=89
WIDTH=1360
HEIGHT=800
SCREEN=0

xdotool windowsize window_id WIDTH HEIGHT

xdotool windowsize 0x04200221 1000 600

#! /bin/sh
fw=`xdotool getwindowfocus`
for nw in `xdotool search --classname Navigator`; do
   test "$fw" = "$nw" && xdotool windowsize "$fw" 800 600
done

nw=`xdotool search --classname Navigator | tail -1`
test "$nw" && xdotool windowsize "$nw" 800 600