text: #include <X11/Xlib.h>
  
  static Display *display;
  
  int x_initialize (char *display_name)
  {
    display = XOpenDisplay (display_name);
    return display != NULL;
  }
  
  char *x_display_name (void)
  {
    return XDisplayName (NULL);
  }
  
  void x_bell (int volume)
  {
    XBell (display, volume);
    XFlush (display);
  }
  