/****** w2.C ******/
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
 Display *disp;
 int ScrNum;
// GC prGC;
// XEvent eEvent;
 Window win;
 
 if ( (disp = XOpenDisplay (NULL)) == NULL)
  {
    printf("\n====1");
    exit(1);
  }
 
 ScrNum = DefaultScreen( disp );
 
 win = XCreateSimpleWindow( disp, RootWindow( disp, ScrNum), 0, 0, 100, 100, 2, 
                                  BlackPixel(  disp, ScrNum), WhitePixel(  disp, ScrNum) );

 XSelectInput( disp, win, ExposureMask|KeyPressMask );

 XMapWindow (disp,win);

 

 XCloseDisplay( disp ); 
 return 0;
}