Detection screen disconnection in linux

We have a nasty little problem. In short we can detect if a screen is c开发者_Python百科onnect when x11 boots (we do this by looking at the log - Xorg.0.log), but we are having trouble detect when are screen is disconnected while the machine is running (ie post x11 boot)

Any one have any ideas?

Cheers

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xrandr prints the status of a screen ("connected", "disabled", "disconnected").

Edit: But at least on my binary-nvidia-driver machine it always reports "connected". I suspect a better driver (e.g. intel, radeon) could work though.