Converting relative URL to absolute

Question

Let\'s say I have a URL of the document linking to another document (which can be both absolute or relative) and I need to have this link in absolute.

I made the sim

Answer 1

$uri = "..";
$path = realpath($uri);
$root = realpath($_SERVER["DOCUMENT_ROOT"]);

if($path){
    $path = str_replace($root, "", $path);
    $path = $_SERVER["SERVER_NAME"] . $path;
    $protocol = "http";
    if(isset($_SERVER["HTTPS"])){
        $protocol .= "s";        
    }
    $path = "{$protocol}://$path";
    $path = str_replace("\\", "/", $path);
}

var_dump($path);

There is probably a better/quicker way, but I just knocked this up...