Automatically switch to big monitor on login

Here's the deal: when I login into my KDE environment, I want system to check if my large monitor is connected and to switch to this monitor if it's found. The laptop screen I want to turn OFF (the system heats up enough with only one screen used; besides, I couldn't find any real use for 2nd monitor, probably because of lack of imagination).

After playing a bit with systemd, I gave up and simply added a script to KDE's autostart.

Here's some information one need to get before you write such a script for your configuration:



1. Connnect your big monitor and then run `xrandr` command in console. You should get output like this:

TODO: put my output here

Notice the following:

• Names of your book and big screens' outputs. In my case they are "LVDS" and "VGA-0";
• Check if native resolution for your big monitor is in the list. If not, you should add it first, as explained here: https://wiki.archlinux.org/index.php/xrandr#Adding_undetected_resolutions Then follow these hints to save this mode persistently: https://wiki.ubuntu.com/X/Config/Resolution#Setting_xrandr_changes_persistently

2. Run the following command: `ls -1 /sys/class/drm/*/status`. The output will be something like this:

/sys/class/drm/card0-HDMI-A-1/status
/sys/class/drm/card0-LVDS-1/status
/sys/class/drm/card0-VGA-1/status

You should write down the file, which is appropriate to your big screen. It can't be "built" by knowing the output name from `xrandr`, as you can see. In my example, xrandr says "VGA-0", but here I get "VGA-1". You don't have to understand it, just accept.


3. Now, we're all good to write the script. I've put it into $HOME/bin/ directory, for example:

#!/bin/sh

# Define some configuration first
export BOOK_OUTPUT="LVDS"
export BOOK_MODE-"1366x768"
export BIG_BROTHER="VGA-0"
export BROTHER_MODE="1920x1080"
export BROTHER_STATUS_FILE="/sys/class/drm/card0-VGA-1/status"

# These vars are required for the script to access user display
export DISPLAY=:0
export XAUTHORITY=/home/$USER/.Xauthority

[[ $(< $BROTHER_STATUS_FILE) == 'connected' ]] && xrandr --output $BIG_BROTHER --mode $BROTHER_MODE --output $BOOK_OUTPUT --off

[[ $(< $BROTHER_STATUS_FILE) == 'disconnected' ]] && xrandr --output $BIG_BROTHER --off --output $BOOK_OUTPUT --mode $BOOK_MODE

exit 0

4. Final step: go to KDE's System Settings :: Autostart and add Script file (chose yours) nad setup is to runt "On startup".