php get url of redirect from source url

Question

I have this link:

http://libero-news.it.feedsportal.com/c/34068/f/618095/s/2e34796f/l/0L0Sliberoquotidiano0Bit0Cnews0C12735670CI0Esaggi0Eper0Ele0Eriforme0Ecostituzionali0EChiaccherano0Ee0Eascoltano0Bhtml/story01.htm

If you visit it, this become:

http://www.liberoquotidiano.it/news/1273567/I-saggi-per-le-riforme-costituzionali-Chiaccherano-e-ascoltano.html

How can I get the second link from the first?

I have tried this but don't work, returning me the same first link:

<?php
$url="http://libero-news.it.feedsportal.com/c/34068/f/618095/s/2e34796f/l/0L0Sliberoquotidiano0Bit0Cnews0C12735670CI0Esaggi0Eper0Ele0Eriforme0Ecostituzionali0EChiaccherano0Ee0Eascoltano0Bhtml/story01.htm";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
$a = curl_exec($ch);
print_r($a);echo"<br>";
if(preg_match('#Location: (.*)#', $a, $r)){
   $l = trim($r[1]);
   echo $l;
}else echo "not working";

Thanks a lot.

Answer 1

Thanks to @king-isaac the following code was tested and it works.

<?php 

$url="http://libero-news.it.feedsportal.com/c/34068/f/618095/s/2e34796f/l/0L0Sliberoquotidiano0Bit0Cnews0C12735670CI0Esaggi0Eper0Ele0Eriforme0Ecostituzionali0EChiaccherano0Ee0Eascoltano0Bhtml/story01.htm";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); // Must be set to true so that PHP follows any "Location:" header
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$a = curl_exec($ch); // $a will contain all headers

$url = curl_getinfo($ch, CURLINFO_EFFECTIVE_URL); // This is what you need, it will return you the last effective URL

// Uncomment to see all headers
/*
echo "<pre>";
print_r($a);echo"<br>";
echo "</pre>";
*/

echo $url; // Voila
?>