$_SESSION variable empty on multiple cURL requests - php

Question

In my first cURL request i upload a file and i set a $_SESSION variable with the name, extension etc. In my second cURL request i want to move the uploaded file from tmp folder to user folder but baddly the $_SESSION variable is empty. why?
first request code code looks like this:
$upload = curl_init();
curl_setopt($upload, CURLOPT_URL, "http://localhost/upload/" );
curl_setopt($upload, CURLOPT_POST, true );
curl_setopt($upload, CURLOPT_RETURNTRANSFER, true );
curl_setopt($upload, CURLOPT_USERAGENT, $_SERVER["HTTP_USER_AGENT"] );
curl_setopt($upload, CURLOPT_HTTPHEADER, array("Set-Cookie: data=" . urldecode($cookie) ));
curl_custom_postfields($upload, $fields, $files);
$res = curl_exec($upload);
curl_close($upload);
and the second request code: following the first request:
$submit = curl_init();
curl_setopt($submit, CURLOPT_URL, "http://localhost/" );
curl_setopt($submit, CURLOPT_RETURNTRANSFER, true );
curl_setopt($submit, CURLOPT_USERAGENT, $_SERVER["HTTP_USER_AGENT"] );
curl_setopt($submit, CURLOPT_POST, count($fields));
curl_setopt($submit, CURLOPT_POSTFIELDS, $fields_string );
curl_setopt($submit, CURLOPT_HEADER, true);
curl_setopt($submit, CURLOPT_HTTPHEADER, array("Cookie: data=" . urldecode($cookie) ));
$res = curl_exec($submit);
curl_close($submit);
is there any option to keep session alive? is the same problem i meet on AJAX requests when i start using javascript with AJAX i think.
my response header:
HTTP/1.1 200 OK
Date: Wed, 04 Mar 2015 02:24:22 GMT
Server: Apache/2.2.12 (Win32) DAV/2 mod_ssl/2.2.12 OpenSSL/0.9.8k mod_autoindex_color PHP/5.3.0 mod_perl/2.0.4 Perl/v5.10.0
X-Powered-By: PHP/5.3.0
Set-Cookie: PHPSESSID=g7hc328ij8lr63mps6ub44gat2; path=/
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Length: 22
Content-Type: text/html

Answer 1

I think you need a cookie jar to keep track of your session:
curl_setopt($ch, CURLOPT_COOKIEJAR, "/tmp/cookies");