Monitor plug autodetection for i3

98-monitorswitch.rules

# This should go in /etc/udev/rules.d
KERNEL=="card0", SUBSYSTEM=="drm", ACTION=="change", RUN+="/usr/local/bin/monitorswitch.sh"

monitorswitch.sh

#!/bin/bash

# You will have to customise the device names and layout to whatever xrandr
# setup is appropriate for your machine. udev will run this script as root,
# which works fine for calling xrandr.

# /etc/udev/rules.d/98-monitorswitch.rules:
# KERNEL=="card0", SUBSYSTEM=="drm", ACTION=="change", RUN+="/usr/local/bin/monitorswitch.sh"

#exec >>/tmp/monitorswitch.log 2>&1

read user dn <<EOF
$(who | perl -lane 'if (/\(:([0-9])+\)/) {print "$F[0] $1"; exit}')
EOF
userhome=$(getent passwd $user | cut -f6 -d:)
export XAUTHORITY=$userhome/.Xauthority
export DISPLAY=:$dn

displays=$(xrandr | perl -lane '/ connected/ && print $F[0]')

echo "connected displays:" $displays

if echo $displays | grep -q DP-2 && echo $displays | grep -q DP-3; then
    xrandr --output DP-2 --auto --right-of LVDS-1 --verbose
    xrandr --output DP-3 --auto --right-of DP-2 --verbose
else
    xrandr --output DP-2 --off
    xrandr --output DP-3 --off
fi