Turn off the linux console display

I needed a way to turn off the display on an old netbook that I am using as a low-powered server. I installed CentOS 5.5 on the netbook and set the ‘inittab’ to boot into console mode by default however I did not know how to turn the display off completely when in console mode. I wanted to do this for various reasons; saving power and reducing the heat generated were my primary concerns.

I was thinking of using ‘setterm’ for this, but I decided to google this first and found the perfect solution in the Arch forums. Just in case that link stops working I’m going to include the script below, hopefully it will be helpful to other people.

#!/bin/bash

###################################################
# Check if X is running or not, turn off monitor, #
# wait for a key press and turn it on again.      #
###################################################

grep_result_file=$PWD'/x_running'

# Check if X is running.
ps -e | grep -e "\bX\b" > $grep_result_file
ps -e | grep -e "\bxorg\b" >> $grep_result_file
ps -e | grep -e "\bxserver\b" >> $grep_result_file

## If you want to check result file, uncomment following lines.
#echo "===== $grep_result_file - begin ====="
#cat $grep_result_file
#echo "===== $grep_result_file -  end  ====="

if [ ! -s $grep_result_file ] || [[ $(tty) =~ tty ]] || [[ $(tty) =~ vc ]]; then
    echo 'Detected X not runnig or you are at console...'
    if [ $UID -ne 0 ]; then
        echo 'You need super user privileges to run this script at console.'
        echo 'Rerun as super user or start X and run from a terminal.'
        exit 0
    fi
    turn_off='vbetool dpms off'
    turn_on='vbetool dpms on'
else
    echo 'Detected X running...'
    turn_off='xset dpms force off'
fi

echo 'Turning off monitor...'
$turn_off

echo 'Waiting for a key press...'
read -n1 -s

echo 'Turning on monitor...'
$turn_on

rm $grep_result_file

echo 'Finished: monitor_off'
kill -9 $PPID