Question

How do I create a PHP script that will redirect to a custom URL when link added in the URL. For instance, when a user visits this:

http://mydomain.com/link.php?=http://www.google.com

It should redirect them instantly to google.

Ideally, is it possible to ensure that the click itself came locally?

I am aware that this is most likely a very basic PHP code but note that my knowledge of it is very limited which is restricting me from writing it.

Answer 1

You can use the HTTP_REFERER of $_SERVER variable to check whether it is from the local domain.

Reference: http://php.net/manual/en/reserved.variables.server.php

For redirection, try using the below

http://mydomain.com/link.php?r=http://www.google.com
header("Location:".$_GET['r']);

Reference: https://www.php.net/manual/en/function.header.php

I hope the following works for you, you can hard code the $domain variable as mydomain.com

$url = "http://www.php.net/index.html";
$domain = str_ireplace('www.', '', parse_url($url, PHP_URL_HOST));
$refDomain = str_ireplace('www.', '', parse_url($_SERVER["HTTP_REFERER"], PHP_URL_HOST));

if(strcmp($domain, $refDomain) == 0)
{
     //your code goes here
     header("Location:".$_GET['r']);
}