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Is there a way to check if a display is powered on in Linux? I tried xrandr and xset but neither of these two gives me any information about monitor power. Using xrandr I can identify if the vga cable is connected but not if power is connected. I need this because many of our lab systems keeps lying unused just because someone pulls out the power cable or something.

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Have you tried doing this? – Hello71 Jul 19 '11 at 14:46

The ddccontrol package communicates with the monitor and can read or set various parameters, including the power. At least with my monitor it is capable of turning it on when I have shut it off with the power button.

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It works only with Mitsubishi, NEC and Samsung only but in our lab all monitors are dell monitors. I have tried it and it is not detecting monitor. – Jatin Kumar Jul 21 '11 at 16:01

I don't think this is possible with normal VGA monitors. The best you can do is determine if the VGA is hooked up, and use DPMS to make sure the monitor doesn't try to sleep on you. I don't think figuring out if somebody has shut off or unplugged the monitor is something you can get from software.

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This is available in some of the monitors like i said above. – Jatin Kumar Jul 22 '11 at 13:31

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