#include <X11/Xlib.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static void walk(Display *d, Window w, int depth) {
  Window root, parent, *children = NULL;
  unsigned int n = 0, i;
  char *name = NULL;
  if (XFetchName(d, w, &name) && name) {
    if (strstr(name, "Dillo") || strstr(name, "Site is online")) printf("%.*s%s\n", depth * 2, "                                ", name);
    XFree(name);
  }
  if (XQueryTree(d, w, &root, &parent, &children, &n)) {
    for (i = 0; i < n; i++) walk(d, children[i], depth + 1);
    if (children) XFree(children);
  }
}
int main(void) {
  Display *d = XOpenDisplay(NULL);
  if (!d) { fputs("XOpenDisplay failed\n", stderr); return 1; }
  walk(d, DefaultRootWindow(d), 0);
  XCloseDisplay(d);
  return 0;
}