Is $_SERVER['REQUEST_SCHEME'] reliable?
php, url-parsing
Solution
It is hard to prove that it is reliable, but it is easy to prove that it is not reliable (if only I could provide a case which it does not work). And I can prove that it is unreliable because it does not work with IIS 7.0 + PHP 5.3
Problem
I recently was seeking a way to properly determine protocol, under which url request was supplied to the server. I watched through `parse_url()` and though `$_SERVER` superglobal variable, and found this: ``` <?php header('Content-Type: text/plain'); print_r($_SERVER); ``` Output: [REQUEST_SCHEME] => http However, I was unable to find it on php.net or Google. Though, I was able to find this question. Q#1: If `$_SERVER['REQUEST_SCHEME']` wasn't documented, then it is probably unreliable, or it can be trusted? I'am using `VC9 PHP 5.4.14 TS` under windows for development. But my production is under ubuntu. Q#2: Is this property also availible under ubuntu linux too?