X11 Secure Template

//g++ -o template template.cpp -L/usr/X11R6/lib -lX11
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <X11/Xlib.h>
#include <assert.h>
#include <unistd.h>
#include <math.h>

#define NIL (0)

using namespace std;

int main(){

Display *dpy = XOpenDisplay(NIL);
assert(dpy);

int blackColor = BlackPixel(dpy,DefaultScreen(dpy));
int whiteColor = WhitePixel(dpy,DefaultScreen(dpy));

printf("Window height, width: \n");
int height,width;
scanf("%d %d",&height,&width);

Window w = XCreateSimpleWindow(dpy,DefaultRootWindow(dpy),0,0,height,width,0,whiteColor,whiteColor);
XSelectInput(dpy,w,StructureNotifyMask);
XMapWindow(dpy,w);

GC gc = XCreateGC(dpy,w,0,NIL);
XSetForeground(dpy,gc,blackColor);

for(;;){
    XEvent e;
    XNextEvent(dpy,&e);
    if(e.type == MapNotify)
        break;
}

//Main goes here...

XFlush(dpy);
sleep(1);
cin.ignore().get();

return 0;
}