<?php
  $browser = $_SERVER['HTTP_USER_AGENT'];
  if (strpos($browser, "Jakarta") !== FALSE
    || strpos($browser, "Java/") !== FALSE
    || strpos($browser, "Slurp/") !== FALSE
    || strpos($browser, "msnbot/") !== FALSE
    || strpos($browser, "Googlebot/") !== FALSE
    || strpos($browser, "apacheHttpClient") !== FALSE
    || strpos($browser, "Baiduspider") !== FALSE
    || strpos($browser, "Apache-Maven/") !== FALSE
    ) {
    echo "404 Not Found";
  }
  else {
    $html = file_get_contents("404.html");
    echo $html;
  }