Is there a way to query the power status of an Xorg/X11 display from command line? I want to know if my laptop LCD is powered on after the screen saver--apparently the backlight is still on. This is despite my gnome-screensaver-preferences setting that after 5 minutes of idling, the display is supposed to go to sleep. I am using Debian 6 and whatever x server comes with it.

I see that upower utility has some nifty switches, but they are not documented.


To test whether your monitor is on or off you can use

$ xset q | grep Monitor
Monitor is On

In order to determine the brightness of your LCD backlight you can run

$ xbacklight
  • The xset that comes with Debian 6 (or more recent Fedora 18 for that matter) does not show monitor status like yours. Which distro is it? The xbacklight utility is good to know (despite not doing/showing what I wanted). Thank you though. – Wirawan Purwanto May 20 '13 at 18:27
  • I'm using Ubuntu 13.04 (is based on Debian) with the proprietary nvidia driver. Maybe it's a driver capability. – Stefan Endrullis May 21 '13 at 16:48

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