Re: gdm and display size

[Colin Watson <cjwatson@debian.org>]

On Mon, Apr 07, 2003 at 02:32:59PM -0400, Matthew Weier O'Phinney wrote:
> This is where it gets a little dicey. One machine I wish to log on from
> is an old P-120 laptop with a 640x480 display; my other displays are all
> 1024x768. 
> 
> Is it possible to detect the resolution of the display on which the
> xdmcp server is drawing? If so, how? I'd like to write a script that
> would load different defaults based on display size.

Yes: you can get it from xdpyinfo. If you want something that requires a
bit less parsing, then try this quick C program or a variant that suits
your needs. It's very stupid and doesn't understand -display arguments
or multiple screens or anything like that, but it may help. Compile with
'gcc -L/usr/X11R6/lib -lX11 dpysize.c -o dpysize'.


#include <stdio.h>
#include <stdlib.h>
#include <X11/Xlib.h>

int main (int argc, char *argv[])
{
    Display *dpy = XOpenDisplay (NULL);
    if (!dpy) {
        fprintf (stderr, "%s: unable to open display \"%s\"\n",
                 argv[0], XDisplayName (NULL));
        exit (1);
    }

    printf ("width: %d\n",  DisplayWidth  (dpy, 0));
    printf ("height: %d\n", DisplayHeight (dpy, 0));

    return 0;
}


Cheers,

-- 
Colin Watson                                  [cjwatson@flatline.org.uk]