Alex Sleat

I have a TV and my monitor connected to my PC by a VGA switch box but what’s annoying is they aren’t the same resolution. This causes problems because I can’t see what I’m doing when I have switched to TV and usually have to leave the setting manager open so that when I change between them I just have to hit return and the resolution changes. That’s great and all but it’s far more effort than I want for something I do fairly often.

My plan was initially to create two xorg.conf files and switch between them using a script, I figured this would be the easiest way even though I haven’t messed around with xorg stuff for a few years ever since things just started working better in Linux. Turns out I couldn’t even find where they keep the xorg.conf file, it sure isn’t in /etc/X11 where it was the last time I looked..

On the search for this file though I came across another useful tool called xrandr, which essentially allows you to change the resolution from the command line.

Xrandr is used to set the size, orientation and/or reflection of the outputs for a
screen. It can also set the screen size.

If invoked without any option, it will dump the state of the outputs, showing the
existing modes for each of them, with a ‘+’ after the preferred mode and a ‘*’
after the current mode.

There are a few global options. Other options modify the last output that is spec‐
ified in earlier parameters in the command line. Multiple outputs may be modified
at the same time by passing multiple –output options followed immediately by
their corresponding modifying options.

For more information on xrandr check out the manual page (or type man xrandr in terminal).

It turns out it’s an extremely easy tool to use, with a command as simple as the following changing the resolution:

xrandr --output VGA1 --mode 1440x900

So the next thing I did was create the following script which allows the resolution to switch between 1440×900 and 1360×768 (my monitor and my TV native resolutions).

#!/bin/bash

TV="1360 x 768"
MONITOR="1440 x 900"

TEST="$(xrandr | grep current | sed -e 's/.*current //;s/, maximum.*//')"

#echo $TEST

if [ "$TEST" == "$MONITOR" ]
        then
                xrandr --output VGA1 --mode 1360x768

elif [ "$TEST" == "$TV" ]
        then
                xrandr --output VGA1 --mode 1440x900

else

        exit

fi

This script simply checks what the current resolution is being used and then toggles between the two set resolutions.