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

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.