How to Determine if LCD Monitor is Turned on From Linux Command Line

Question

How do you tell if a computer\'s monitor(s) are turned on/off from the command line in Linux? I\'ve traditionally thought of monitors as output-only devices, but I\'ve noticed t

Answer 1

From systembash.com, here is the code taken from the link, in case it will be down some day:

#!/bin/bash
export DISPLAY=:0.0

if [ $# -eq 0 ]; then
  echo usage: $(basename $0) "on|off|status"
  exit 1
fi

if [ $1 = "off" ]; then
  echo -en "Turning monitor off..."
  xset dpms force off
  echo -en "done.\nCheck:"
  xset -q|grep "Monitor is"
elif [ $1 = "on" ]; then
  echo -en "Turning monitor on..."
  xset dpms force on
  echo -en "done.\nCheck:"
  xset -q|grep "Monitor is"
elif [ $1 = "status" ]; then
  xset -q|sed -ne 's/^[ ]*Monitor is //p'
else 
  echo usage: $(basename $0) "on|off|status"
fi