I've made a script for you:
#!/bin/bash
#
# by desgua
#
# To make the window with a lower hight just like the width.
#############################################################
win=`xdotool getactivewindow`
w=`xwininfo -id $win | grep "Width" | awk '{print $2}'`
#h=`xwininfo -id $win | grep "Height" | awk '{print $2}'`
xdotool windowsize $win $w $w
exit 0
If you're lazy, run this at terminal, and skip to step "6":
cd ~/ && wget dl.dropbox.com/u/4098082/resize.sh && chmod +x ~/resize.sh && ~/resize.sh && rm ~/resize.sh
Step by step instructions:
1) We will need XDoTool and Compiz.
(You can install these from the software center (or by clicking here))
2) Make a file .resize.sh
in your home folder.
3) Paste the above script into it.
4) Make it executable (Here's how to do that).
5) Open Compiz (Menu > System > Preferences > CompizConfig Manager)
6) Go to Commands and add ~/.resize.sh
to one command
7) Then go to Keybindings and make a shortcut for it.