Script to enable and disable the HDMI signal of the Raspberry PI

raspi-monitor

#!/bin/bash -e

# /usr/local/sbin/raspi-monitor
# Script to enable and disable the HDMI signal of the Raspberry PI
# Inspiration: http://www.raspberrypi.org/forums/viewtopic.php?t=16472&p=176258

CMD="$1"

function on {
    /opt/vc/bin/tvservice --preferred

    # Hack to enable virtual terminal nr 7 again:
    chvt 6
    chvt 7
}

function off {
    /opt/vc/bin/tvservice --off
}

function must_be_root {
    if [ $USER != root ]; then
        echo "ERROR: Script must be executed as the root user"
        exit 1
    fi
}

function main {
    must_be_root
    if [ "$CMD" == "on" ]; then
        on
    elif [ "$CMD" == "off" ]; then
        off
    else
        echo "Usage: $0 <on|off>"
        exit 1
    fi
    exit 0
}

main

raspi-monitor-scheduler

# /etc/cron.d/raspi-monitor-scheduler

# Enable the monitor every weekday morning at 8:00
0 8 * * 1,2,3,4,5 root /usr/local/sbin/raspi-monitor on > /dev/null 2>&1

# Disable the monitor every weekday evening at 17:30
30 17 * * 1,2,3,4,5 root /usr/local/sbin/raspi-monitor off > /dev/null 2>&1

Hi,
in order to have the monitor output only shown, when there is no holiday, I added this 2 sections:
at line 7

###############################################
TODAY=$(date +%Y-%m-%d)
###############################################

after line 30,
###############################################
if grep -q $TODAY /home/pi/holidays.txt; then
echo Skipping holiday for $*
echo "Today $TODAY is a holiday!" >> /home/pi/today-is-a-holiday.txt
off
exit 0
fi
###############################################

Created a file: /home/pi/holidays.txt with a holiday on each line, e.g.

2021-11-01