Maximize a running program with bash & xdotool

#!/bin/bash
PROG='thunderbird'; # set to your program process name
RUNNING=`ps auxw | grep $PROG | grep -v grep | wc -l`
if [ "$RUNNING" == "1" ]; then
 # get PID
 PID=`ps auxw | grep $PROG | grep -v grep | awk '{print $2}'`
 # get window ID from PID
 WINID=`xdotool search --pid $PID | tail -1`
 # focus window, wait until focused, maximize with shortcut
 xdotool windowactivate --sync $WINID key --clearmodifiers --delay 100 ctrl+super+Up
else
 # not running, run it
 $PROG
fi