A quick script to control the power state of a TV attached to a Raspberry Pi over HDMI. Requires `cec-utils` to be installed.

toggle-tv-power off.sh

#!/usr/bin/env bash

iso8601_date () {
  date +%Y-%m-%dT%H:%M:%S%z
}

turn_on () {
  echo 'on 0' | cec-client -s -d 1 RPI
}

turn_off () {
  echo 'standby 0' | cec-client -s -d 1 RPI
}

args="$1"

case $args in
  on)
  echo "[$(iso8601_date)]: Turning the TV on"
  turn_on
  ;;

  off)
  echo "[$(iso8601_date)]: Turning the TV off"
  turn_off
  ;;

  auto)
  echo "[$(iso8601_date)]: Checking the TV power state"
  if [[ $(echo 'pow 0' | cec-client -s -d 1 RPI) =~ "power status: standby" ]]; then
    echo "[$(iso8601_date)]: The TV appears to be off, turning it on now"
    turn_on
  else
    echo "[$(iso8601_date)]: The TV appears to be on, turning it off now"
    turn_off
  fi
  ;;

  *)
  echo "Usage:"
  echo "  toggle-tv-power on|off|auto"
  exit 1
esac

echo "---"