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Kevin Ryde > X11-Protocol-Other-29 > X11::Protocol::Ext::XINERAMA



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Module Version: 29   Source   Latest Release: X11-Protocol-Other-30


X11::Protocol::Ext::XINERAMA - multi-monitor display information


 use X11::Protocol;
 my $X = X11::Protocol->new;
   or print "XINERAMA extension not available";


Xinerama puts together two or more physical monitors to make a single large screen. The XINERAMA extension allows clients to enquire about the setup.

The 1.0 "PanoramiX" requests take a $window parameter apparently to allow for more than one X screen made up of multiple physical monitors, but in practice the servers have only made one screen this way and the 1.1 "Xinerama" requests don't have that.

See examples/ in the sources for a sample program dumping the Xinerama state information.


The following requests are made available with an init_extension() per "EXTENSIONS" in X11::Protocol.

    my $bool = $X->init_extension('XINERAMA');

Xinerama 1.0

($server_major, $server_minor) = $X->PanoramiXQueryVersion ($client_major, $client_minor)

Negotiate a protocol version with the server. $client_major and $client_minor is what the client would like, the returned $server_major and $server_minor is what the server will do, which might be less than requested (but not more).

The current code in this module supports up to 1.1. The intention would be to automatically negotiate within init_extension() if/when necessary,

$flag = $X->PanoramiXGetState ($window)

Return non-zero if Xinerama is active on the screen of $window (an XID).

$count = $X->PanoramiXGetScreenCount ($window)

Return the number of physical monitors on the screen of $window (an XID).

($width, $height) = $X->PanoramiXGetScreenSize ($window, $monitor)

Return the size in pixels of physical monitor number $monitor (integer, 0 for the first monitor) on the screen of $window (an XID).

Xinerama 1.1

$bool = $X->XineramaIsActive ()

Return non-zero if Xinerama is active on the $X server.

@rectangles = $X->XineramaQueryScreens ()

Return the rectangular areas made up by the physical monitors. The return is a list of arrayrefs,

    [ $x,$y, $width,$height ]

$x,$y is the top-left corner of the monitor in the combined screen.



Rumour has it the Xsun server with Xinerama 1.0 had a different request number 4 than the XineramaIsActive of Xinerama 1.1 above.

There's no attempt to do anything about this here, as yet. If PanoramiXQueryVersion() reports 1.0 then you shouldn't use XineramaIsActive() anyway, so no clash. If you do and it's the Xsun server then expect either a Length error reply, or the server to adapt itself to the request length and behave as XineramaIsActive.

PanoramiXGetScreenSize() Buffer Overrun

Early server code such as X11R6.4 might not range check the monitor number in PanoramiXGetScreenSize(). Did big values read out fragments of arbitrary memory, or cause a segfault? Don't do that. some time post 1.5.x, "Prevent buffer overrun in ProcPanoramiXGetScreenSize",


To simulate some Xinerama for testing the Xdmx server can multiplex together two or more other servers to present one big screen. Those sub-servers can even be Xnest or Xephyr windows on an existing X display. For example running up Xdmx as display ":102",

    Xephyr :5 -screen 200x100 &
    Xephyr :6 -screen 190x110 &
    sleep 1
    Xdmx -display :5 -display :6 +xinerama -input :5 -input :6 :102

Xephyr implements some extensions natively, whereas Xnest relies on the target server capabilities. Or to run up without bothering to look at anything Xvfb in memory or a disk file.



Initial technical details



Copyright 2011, 2012, 2013 Kevin Ryde

X11-Protocol-Other is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

X11-Protocol-Other is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with X11-Protocol-Other. If not, see <>.

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