#linux monitor primary

This works perfectly on my version of Ubuntu.

http://www.thetechrepo.com/main-articles/502-how-to-change-the-primary-monitor-in-ubuntu-or-other-linux-distributions

First make an empty shell script file <name>.sh

#!/bin/bash

# Author: Andrew Martin

# Credit: http://ubuntuforums.org/showthread.php?t=1309247

echo "Enter the primary display from the following:" # prompt for the display

xrandr --prop | grep "[^dis]connected" | cut --delimiter=" " -f1 # query connected monitors

read choice # read the users's choice of monitor

xrandr --output $choice --primary # set the primary monitor

Then run the script after making it executable by chmod +x <name>.sh

Then run it ./<name>.sh

You should be monitors as printed out. Type in the monitor that you want to use as a primary.