setup environment based on a connected display

setup-tv.desktop

# place in /usr/share/gdm/greeter/autostart/setup-tv.desktop
[Desktop Entry]
Type=Application
Name=Setup TV
Exec=/home/ichi/bin/setup_tv.zsh
NoDisplay=true
X-GNOME-AutoRestart=true

setup_tv.zsh

#!/usr/bin/env zsh
if [ "$(md5sum /sys/class/drm/card0-HDMI-A-1/edid)" = "82e44c737eaede4d7e947d1579d24474  /sys/class/drm/card0-HDMI-A-1/edid" ]; then
	echo "Identified the Samsung TV in the bedroom"
  
  # set underscan
	xrandr --output HDMI-0 --set underscan on
	xrandr --output HDMI-0 --set "underscan hborder" 48 --set "underscan vborder" 24
	
  # disable laptop display
	xrandr --output VGA-0 --off --output LVDS --off --output HDMI-0 --primary --mode 1920x1080 --pos 118x184 --rotate normal
  
  # set a dpi of 200 so everything scales so I can see it from the couch
	tmp="$(mktemp)"
	echo "Xft.dpi: 200" > "$tmp"
	xrdb -merge "$tmp"
	notify-send hello "from tv"
fi