[plug] Detecting an external monitor before X starts

[Steve Baker]

Hi PLUG,

I'm running the beryl window manager, which can't run properly in X 
'multi-head' mode, although it's fine with nvidia's TwinView mode.  
However, TwinView doesn't really behave properly if I _don't_ have an 
external monitor plugged in.  My current solution is to run two 
different xorg.conf files (one with multi-head config and one with 
twinview config) and switch between them.  Some googling tells me that 
other people are doing something similar.

What I would like to do is to detect at system boot time (BEFORE X 
starts) if an external monitor is present, and pre-set the appropriate 
xorg.conf file accordingly - rather than wait for the boot to finish, 
then switch to VT1, change the config, restart GDM, etc.  Does anyone 
know how I might be able to do this?  The only tools I've found so far 
to detect this (eg. nvidia-settings) require X to be already running, 
which is too late.

Any tips greatly appreciated.

Regards,
Steve