# Getting info about attached displays **URL:** \ **Category:** Ruby\ **Created:** [January 13, 2009, 6:01pm UTC](https://www.ruby-forum.com/t/getting-info-about-attached-displays/157609 "2009-01-13T18:01:52Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![philswenson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/7feea3/32.png) [@philswenson](https://www.ruby-forum.com/u/philswenson)\ **Post date:** [January 13, 2009, 6:01pm UTC](https://www.ruby-forum.com/t/getting-info-about-attached-displays/157609/1 "2009-01-13T18:01:52Z")
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! ---
**Author:** ![philswenson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/7feea3/32.png) [@philswenson](https://www.ruby-forum.com/u/philswenson)\ **Post date:** [January 13, 2009, 6:49pm UTC](https://www.ruby-forum.com/t/getting-info-about-attached-displays/157609/2 "2009-01-13T18:49:54Z")
On Tue, Jan 13, 2009 at 11:01 AM, Phil S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) 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/](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](http://x.org) or [xfree86.org](http://xfree86.org). –Kyle ---
**Author:** ![philswenson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/7feea3/32.png) [@philswenson](https://www.ruby-forum.com/u/philswenson)\ **Post date:** [January 13, 2009, 7:00pm UTC](https://www.ruby-forum.com/t/getting-info-about-attached-displays/157609/3 "2009-01-13T19:00:55Z")
Kyle S. wrote: > On Tue, Jan 13, 2009 at 11:01 AM, Phil S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) 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/](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](http://x.org) or [xfree86.org](http://xfree86.org). > > –Kyle Thanks Kyle, Yes… I realise now that it is more OS based (though I still can’t find the windows command for it!). The problem with xdpyinfo is that number of screens is actually NOT the number of displays. I have 2 monitors attached and I get the answer of 1, because I have one virtual desktop spanning the two. Anyway… off topic! Thanks again ---
**Author:** ![philswenson](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/7feea3/32.png) [@philswenson](https://www.ruby-forum.com/u/philswenson)\ **Post date:** [January 13, 2009, 9:40pm UTC](https://www.ruby-forum.com/t/getting-info-about-attached-displays/157609/4 "2009-01-13T21:40:23Z")
Phil, there are two ways you can have two monitors being a virtual display, the driver may take care of it (like the nvidia one, and I have no way of knowing how to detect that), or it may be through xinerama. If it’s through xinerama, you should be able to tell what the geometries and positions of the component screens are, even if you use it as one huge screen.