Simple Linux X11 Window

#include <X11/Xlib.h>

int main() {

  XEvent e;
  Display * d = XOpenDisplay(NULL);
  int s = DefaultScreen(d);
  Window w = XCreateSimpleWindow(d, RootWindow(d, s), 0, 0, 100, 100, 1, BlackPixel(d, s), WhitePixel(d, s));
  XSelectInput(d, w, ExposureMask | KeyPressMask);
  XMapWindow(d, w);

  while (1) {
    XNextEvent(d, & e);
  }

  XCloseDisplay(d);
  return 0;
}