Download file Curl with url var - php

Question

I would like to download a file with Curl.
The problem is that the download link is not direct, for example:
http://localhost/download.php?id=13456
When I try to download the file with curl, it download the file download.php!
Here is my curl code:
###
function DownloadTorrent($a) {
$save_to = $this->torrentfolder; // Set torrent folder for download
$filename = str_replace('.torrent', '.stf', basename($a));
$fp = fopen ($this->torrentfolder.strtolower($filename), 'w+');//This is the file where we save the information
$ch = curl_init($a);//Here is the file we are downloading
curl_setopt($ch, CURLOPT_ENCODING, "gzip"); // Important
curl_setopt($ch, CURLOPT_TIMEOUT, 50);
curl_setopt($ch, CURLOPT_URL, $fp);
curl_setopt($ch, CURLOPT_HEADER,0); // None header
curl_setopt($ch, CURLOPT_BINARYTRANSFER,1); // Binary trasfer 1
curl_exec($ch);
curl_close($ch);
fclose($fp);
}
Is there a way to download the file without knowing the path?

Answer 1

You may try CURLOPT_FOLLOWLOCATION
TRUE to follow any "Location: " header that the server sends as part
of the HTTP header (note this is recursive, PHP will follow as many
"Location: " headers that it is sent, unless CURLOPT_MAXREDIRS is
set).
So it will result into:
function DownloadTorrent($a) {
$save_to = $this->torrentfolder; // Set torrent folder for download
$filename = str_replace('.torrent', '.stf', basename($a));
$fp = fopen ($this->torrentfolder.strtolower($filename), 'w+');//This is the file where we save the information
$ch = curl_init($a);//Here is the file we are downloading
curl_setopt($ch, CURLOPT_ENCODING, "gzip"); // Important
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 50);
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER,0); // None header
curl_setopt($ch, CURLOPT_BINARYTRANSFER,1); // Binary transfer 1
curl_exec($ch);
curl_close($ch);
fclose($fp);
}

Answer 2

Set the FOLLOWLOCATION option to true, e.g.:
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
Options are documented here: http://www.php.net/manual/en/function.curl-setopt.php

Answer 3

Oooh !
CURLOPT_FOLLOWLOCATION work perfect...
The problem is that I use CURLOPT_URL for fopen(), I simply change CURLOPT_URL whit CURLOPT_FILE
and it works very well!
thank you for your help =)