Check if the Jquery CDN protocol relative url exists PHP - php

Question

I am trying to see if JQuery CDN exists or not via PHP
essentially what Paul Irish did here but with PHP instead.
http://paulirish.com/2010/the-protocol-relative-url/
I am trying following but it's not working. Is this possible without http/https?
This is based on How can I check if a URL exists via PHP?
$jquery_cur = '1.9.1'; // JQuery Version
$jquery_cdn = '//code.jquery.com/jquery-'.$jquery_cur.'.min.js';
$jquery_local = '/assets/js/libs/jquery-'.$jquery_cur.'.min.js';
$jquery_ver = $jquery_cdn; //Load the Jquery CDN version by default
$cdn_headers = #get_headers($jquery_ver);
if(strpos($cdn_headers[0], '404 Not Found')) {
$jquery_ver = $jquery_cdn;
}
else {
$jquery_ver = $jquery_local;
}

Answer 1

Hi check this solution you were check header without any protocol you need to add http or https to check files. test it with or without your internet connection.
$jquery_cur = '1.9.1'; // JQuery Version
$jquery_cdn = '//code.jquery.com/jquery-'.$jquery_cur.'.min.js';
$jquery_local = '/assets/js/libs/jquery-'.$jquery_cur.'.min.js';
$jquery_ver = $jquery_cdn; //Load the Jquery CDN version by default
$jquery_url = ( $_SERVER['SERVER_PORT'] == 443 ? "https:" : "http:").$jquery_cdn;
$test_url = #fopen($jquery_url,'r');
if($test_url === False) {
$jquery_ver = $jquery_local;
}
echo $jquery_ver;
with get_header
$headers = #implode('', #get_headers($jquery_url));
$test_url = (bool)preg_match('#^HTTP/.*\s+[(200|301|302)]+\s#i', $headers);
if($test_url === False) {
$jquery_ver = $jquery_local;
}
echo $jquery_ver;