Grabbing Destination Link of a Redirect - php

Question

Hopefully I am just overlooking this.
I am trying to grab the destination URL of a redirect link using PHP. It's to get the site URL of an affiliate/cloaked link.
Best example: http://tinyurl.com/2tx goes to google.com
NOTE: This is an example, the links are created dynamically
Right now I pass the URL through
www.mysite.com/redirect.php?link=http://tinyurl.com/2tx
Here is the code from the site - NOTE: since the URL has Ampersands in them I had to go this route over GET.
<?php
$name = http_build_query($_GET);
// which you would then may want to strip away the first 'name='
$name = substr($name, strlen('name='));
//change link to a nice URL
$url = rawurldecode($name);
?>
I have a simple script that grabs the URL, how could I process the URL to get the destination URL?
Hopefully that's not too confusing.
Cheers,
Robb

Answer 1

You should post some of your code next time. I assume you are using cURL to do this. It's fairly simple:
//sanitize
$ch = curl_init($_GET['link']);
//follow redirects
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_exec($ch);
$url = curl_getinfo($ch, CURLINFO_EFFECTIVE_URL);
EDIT: per Dagon, you just want to "know the url but not go there." It is more efficient to use this setting if you only need to know the url but not get its contents:
curl_setopt($ch, CURLOPT_NOBODY, true);

Answer 2

Here is how I would do it (Read the comments):
<?php
// Connect to the page:
$ch = curl_init("http://tinyurl.com/2tx");
// Don't get the body (remove if you want the body):
curl_setopt($ch, CURLOPT_NOBODY, true);
// Follow the page redirects:
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
// Retun the data as a string (Remove to echo to the page):
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
// Execute:
curl_exec($ch);
// Get data:
print_r($data = curl_getinfo($ch));
// Get just the url:
echo $data["url"];

Answer 3

Make a HTTP HEAD Request to the URL you have. You will get back an HTTP 301 or 302 response with the destination URL.
Example: Put your URL here to see the response returned when making an HTTP Head Request.

Answer 4

This might be an encoding issue. The parameter in your URL is not encoded, so it's probably damaged when trying to get it using $_GET.
You want to use this URL:
www.mysite.com/redirect.php?link=http%3A%2F%2Ftinyurl.com%2F2tx
You can encode URL variables in PHP using the urlencode() function. The variable that (I think) you want can now be accessed like this:
echo $_GET['link']; // http://tinyurl.com/2tx