From: Kyle Schmitt <kyleaschmitt@...>
Date: 2009-01-14T02:48:07+09:00
Subject: Re: getting info about attached displays

On Tue, Jan 13, 2009 at 11:01 AM, Phil Smy <phil@philsmy.com> wrote:
> Hi,
> I have a ruby daemon process that needs to get info about the monitors
> attached to the machine it is running on. Does anyone have any nice
> x-platform way of doing this? Barring that, how about some Windows
> calls?
>
> Thanks!
> --
> Posted via http://www.ruby-forum.com/.
Phil, that's really more of a general unix (or DOS in the case of
windows) question.

Still, for real OSes running X, xdpyinfo is a utility that provides
tons of info, including the number of attached screens...

irb>%x[xdpyinfo][/number of screens: +[0-9]+/]
=> "number of screens:    1"

I'd suggest just running it into less, so you can get acquainted with
it's output.  The man page sadly doesn't point you to useful C calls,
but the source should be decently documented if you want to grab it
from x.org or xfree86.org.

--Kyle