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From: klute@tommy.informatik.uni-dortmund.de (Rainer Klute)
Newsgroups: comp.windows.x
Subject: Re: Remote Xserver shutdown
Keywords: PC X Sight
Message-ID: <3125@laura.UUCP>
Date: 26 Mar 91 08:49:19 GMT
References: <62@uarthur.UUCP>
Sender: news@laura.UUCP
Reply-To: klute@tommy.informatik.uni-dortmund.de (Rainer Klute)
Organization: University of Dortmund, Germany
Lines: 92

In article <62@uarthur.UUCP>, wds@uarthur.UUCP (William D. Sheppard) writes:
|> I am trying to figure out a way to kill a PC XSight Server
|> from unix. Basically when using PC Xsight, the server is running
|> on the PC and my clients are running on SPARC stations. When the
|> client exits my aplication I want to be able to return the user
|> back to DOS. Is their anything defined in the X protocol to get
|> a X Server to commit suicide?

Not directly (as far as I know). But you could try the following: Open the
display without creating a window, traverse the window hierarchy (to be
obtained by XQueryTree) and kill (XKillWindow) each window you find. If you
then close your own display connection the server might reset. "Might"
because there might be other display connections without windows which
cannot be destroyed by the XQueryTree/XKillWindow procedure. And if you are
lucky your server will terminate if it has no more connections to clients.

Here is some code to show how to do it:


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


static IgnoreErrors (display, event)
Display *display;
XErrorEvent event;
{
}


static KillWindows (display, window)
Display *display;
Window window;
{
    Window       root, parent, *children;
    int          child;
    unsigned int noChildren = 0;

    XSetErrorHandler (IgnoreErrors);
    while (XQueryTree (display, window, &root, &parent, &children,
		       &noChildren))
    {
	if (noChildren <= 0)
	    break;
	for (child = 0; child < noChildren; child++)
	    XKillClient (display, children[child]);
	XFree ((char *) children);
    };
}




main (argc, argv)
int argc;
char *argv[];
{
    Display *display;
    int     screen;
    Window  rootWindow;

    if (argc != 2)
    {
	fprintf (stderr, "Usage: %s display\n", argv[0]);
	exit (1);
    };

    display = XOpenDisplay (argv[1]);
    if (display == (Display *) 0)
    {
	fprintf (stderr, "Could not open display %s.\n", argv[1]);
	exit (1);
    };

    fprintf (stdout, "Killing all windows on display %s", argv[1]);
    fflush (stdout);
    for (screen = 0; screen < ScreenCount (display); screen++)
    {
	rootWindow = RootWindow (display, screen);
	KillWindows (display, rootWindow);
    };
    XSync (display, False);
    fprintf (stdout, ", done.\n");
}


-- 
  Dipl.-Inform. Rainer Klute      klute@irb.informatik.uni-dortmund.de
  Univ. Dortmund, IRB             klute@unido.uucp, klute@unido.bitnet
  Postfach 500500         |)|/    Tel.: +49 231 755-4663
D-4600 Dortmund 50        |\|\    Fax : +49 231 755-2386