display magic

99-displaymagic.rules

#/etc/udev/rules.d/99-displaymagic.rules
# enable LVDS on HDMI disconnect
SUBSYSTEM=="drm", ACTION=="change", RUN+="/usr/local/bin/displaymagic.sh"

displaymagic.sh

#!/bin/bash
#
# display magic v0.1.0
#
# The following script toggles between the internal monitor and an external
# monitor.
#
# by XenGi
##### edit config #####

EXTERNAL="HDMI1"
#TODO: EXTERNAL2="VGA1"
INTERNAL="LVDS1"
export DISPLAY=":0.0"
USER="bob"

#USER=$(who | grep $DISPLAY\) | head -1 | cut -f 1 -d ' ')

##### end config  #####

# Check if we are root
if [[ $EUID -ne 0 ]] ; then
    echo "This script must be run as root" 
    exit 1
fi

# check for udev rule
if [[ ! -f /etc/udev/rules.d/99-displaymagic.rules ]] ; then
    echo "No udev rule found. Put '99-displaymagic.rules' in '/etc/udev/rules.d' and execute 'udevadm control --reload' as root."
    exit
fi

# the script
export XAUTHORITY="/home/$USER/.Xauthority"

# just wait a second so that things run smooth
sleep 1

STATUS=$(su $USER -c "xrandr --current | grep $EXTERNAL | cut -d \  -f 2")
if [[ "$STATUS" == "disconnected" ]] ; then
    # switch HDMI on and LVDS off
    su $USER -c "xrandr --output $INTERNAL --off"
    su $USER -c "xrandr --output $EXTERNAL --auto"
    # set HDMI output as primary audio
    su $USER -c "pactl set-card-profile 0 output:hdmi-surround"
fi

#TODO: add the same funcionality for the VGA port.
#STATUS="`su $USER -c "xrandr --current | grep $EXTERNAL2 | cut -d \  -f 2"`"
#if [[ "$STATUS" == "disconnected" ]] ; then
#    # switch VGA on and LVDS off
#    su $USER -c "xrandr --output $INTERNAL --off"
#    su $USER -c "xrandr --output $EXTERNAL2 --auto"
#    # set internal speakers and mic as primary audio
#    su $USER -c "pactl set-card-profile 0 output:analog-stereo+input:analog-stereo"
#fi

if [[ "$STATUS" == "connected" ]] ; then
    # switch HDMI off and LVDS on
    su $USER -c "xrandr --output $EXTERNAL --off"
    su $USER -c "xrandr --output $INTERNAL --auto"
    # set internal speakers and mic as primary audio
    su $USER -c "pactl set-card-profile 0 output:analog-stereo+input:analog-stereo"
fi

Are the behaviors opposite in the connected/disconnected case? For example, in connected, the external is turned off.

yes, it's the oppisite. I've no idea why, but it only works this way. Seems like if you fire the xrandr command on an udev rule you only get the last state, not the currently active.

XenGi, that was really useful to me. Thanks. Might be a missing quote on line 39.