control hdmi display via cec from raspberry pi

control-display.sh

#/bin/bash
# see https://www.screenly.io/blog/2017/07/02/how-to-automatically-turn-off-and-on-your-monitor-from-your-raspberry-pi/#cec-client
# and crontab -e (of user "pi") --Andi

case "$1" in
on)
	echo 'on 0' | cec-client -s -d 1
	;;
off)
	echo 'standby 0' | cec-client -s -d 1
	;;
status)
	echo 'pow 0' | cec-client -s -d 1
	;;
*)
	echo $"Usage: $0 {on|off|status}"
	exit 1

esac