//******************************************************************************
// Copyright (c) 2009 Alexey Smirnov. All rights reserved.
//******************************************************************************
#define NEED_DBE_PROTOCOL

#include <stdlib.h>
#include <stdio.h>
#include <X11/Xlibint.h>
#include <X11/Xlib.h>
#include <X11/extensions/Xdbeproto.h>
int main () {
//Vars
Display                       *FPDisplay;
int                           FMajorOpcode;
int                           F1stEvent;
int                           F1stError;
xDbeGetVersionReq             FPReq;
xDbeGetVersionReply           FReply;

//Opening the Display
FPDisplay = XOpenDisplay (0);
if (FPDisplay) {
  if (XQueryExtension(FPDisplay,"DOUBLE-BUFFER",&FMajorOpcode,&F1stEvent,&F1stError)) {
//Printing XQueryExtension results
   printf ("DOUBLE-BUFFER OpCode is: %lu, 1stEvent is: %lu, 1stError is: %lu",FMajorOpcode,F1stEvent,F1stError);

   FPReq.reqType     = FMajorOpcode;
   FPReq.dbeReqType  = X_DbeGetVersion;
   FPReq.length      = sz_xDbeGetVersionReq >> 2;
   FPReq.majorVersion= 0;
   FPReq.minorVersion= 0;
//Trying to do _XSend()/_XReply()
   _XSend (FPDisplay,&FPReq,sz_xDbeGetVersionReq);
   if (_XReply (FPDisplay,&FReply,0,1)) {
//Printing DOUBLE-BUFFER version
    printf ("DOUBLE-BUFFER version is: %lu.%lu",FReply.majorVersion,FReply.minorVersion);
   }
  }
//Closing the Display
XCloseDisplay(FPDisplay);
}
return 0;
}