Solution 1:

You can specify the cookie file with a curl opt. You could use a unique file for each user.

curl_setopt( $curl_handle, CURLOPT_COOKIESESSION, true );
curl_setopt( $curl_handle, CURLOPT_COOKIEJAR, uniquefilename );
curl_setopt( $curl_handle, CURLOPT_COOKIEFILE, uniquefilename );

The best way to handle it would be to stick your request logic into a curl function and just pass the unique file name in as a parameter.

    function fetch( $url, $z=null ) {
            $ch =  curl_init();

            $useragent = isset($z['useragent']) ? $z['useragent'] : 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0.2) Gecko/20100101 Firefox/10.0.2';

            curl_setopt( $ch, CURLOPT_URL, $url );
            curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
            curl_setopt( $ch, CURLOPT_AUTOREFERER, true );
            curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
            curl_setopt( $ch, CURLOPT_POST, isset($z['post']) );

            if( isset($z['post']) )         curl_setopt( $ch, CURLOPT_POSTFIELDS, $z['post'] );
            if( isset($z['refer']) )        curl_setopt( $ch, CURLOPT_REFERER, $z['refer'] );

            curl_setopt( $ch, CURLOPT_USERAGENT, $useragent );
            curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, ( isset($z['timeout']) ? $z['timeout'] : 5 ) );
            curl_setopt( $ch, CURLOPT_COOKIEJAR,  $z['cookiefile'] );
            curl_setopt( $ch, CURLOPT_COOKIEFILE, $z['cookiefile'] );

            $result = curl_exec( $ch );
            curl_close( $ch );
            return $result;
    }

I use this for quick grabs. It takes the url and an array of options.

Solution 2:

In working with a similar problem I created the following function after combining a lot of resources I ran into on the web, and adding my own cookie handling. Hopefully this is useful to someone else.

      function get_web_page( $url, $cookiesIn = '' ){
        $options = array(
            CURLOPT_RETURNTRANSFER => true,     // return web page
            CURLOPT_HEADER         => true,     //return headers in addition to content
            CURLOPT_FOLLOWLOCATION => true,     // follow redirects
            CURLOPT_ENCODING       => "",       // handle all encodings
            CURLOPT_AUTOREFERER    => true,     // set referer on redirect
            CURLOPT_CONNECTTIMEOUT => 120,      // timeout on connect
            CURLOPT_TIMEOUT        => 120,      // timeout on response
            CURLOPT_MAXREDIRS      => 10,       // stop after 10 redirects
            CURLINFO_HEADER_OUT    => true,
            CURLOPT_SSL_VERIFYPEER => true,     // Validate SSL Certificates
            CURLOPT_HTTP_VERSION   => CURL_HTTP_VERSION_1_1,
            CURLOPT_COOKIE         => $cookiesIn
        );

        $ch      = curl_init( $url );
        curl_setopt_array( $ch, $options );
        $rough_content = curl_exec( $ch );
        $err     = curl_errno( $ch );
        $errmsg  = curl_error( $ch );
        $header  = curl_getinfo( $ch );
        curl_close( $ch );

        $header_content = substr($rough_content, 0, $header['header_size']);
        $body_content = trim(str_replace($header_content, '', $rough_content));
        $pattern = "#Set-Cookie:\\s+(?<cookie>[^=]+=[^;]+)#m"; 
        preg_match_all($pattern, $header_content, $matches); 
        $cookiesOut = implode("; ", $matches['cookie']);

        $header['errno']   = $err;
        $header['errmsg']  = $errmsg;
        $header['headers']  = $header_content;
        $header['content'] = $body_content;
        $header['cookies'] = $cookiesOut;
    return $header;
}

Solution 3:

First create temporary cookie using tempnam() function:

$ckfile = tempnam ("/tmp", "CURLCOOKIE");

Then execute curl init witch saves the cookie as a temporary file:

$ch = curl_init ("http://uri.com/");
curl_setopt ($ch, CURLOPT_COOKIEJAR, $ckfile);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, true);
$output = curl_exec ($ch);

Or visit a page using the cookie stored in the temporary file:

$ch = curl_init ("http://somedomain.com/cookiepage.php");
curl_setopt ($ch, CURLOPT_COOKIEFILE, $ckfile);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, true);
$output = curl_exec ($ch);

This will initialize the cookie for the page:

curl_setopt ($ch, CURLOPT_COOKIEFILE, $ckfile);

Solution 4:

Here you can find some useful info about cURL & cookies http://docstore.mik.ua/orelly/webprog/pcook/ch11_04.htm .

You can also use this well done method https://github.com/alixaxel/phunction/blob/master/phunction/Net.php#L89 like a function:

function CURL($url, $data = null, $method = 'GET', $cookie = null, $options = null, $retries = 3)
{
    $result = false;

    if ((extension_loaded('curl') === true) && (is_resource($curl = curl_init()) === true))
    {
        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_FAILONERROR, true);
        curl_setopt($curl, CURLOPT_AUTOREFERER, true);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);

        if (preg_match('~^(?:DELETE|GET|HEAD|OPTIONS|POST|PUT)$~i', $method) > 0)
        {
            if (preg_match('~^(?:HEAD|OPTIONS)$~i', $method) > 0)
            {
                curl_setopt_array($curl, array(CURLOPT_HEADER => true, CURLOPT_NOBODY => true));
            }

            else if (preg_match('~^(?:POST|PUT)$~i', $method) > 0)
            {
                if (is_array($data) === true)
                {
                    foreach (preg_grep('~^@~', $data) as $key => $value)
                    {
                        $data[$key] = sprintf('@%s', rtrim(str_replace('\\', '/', realpath(ltrim($value, '@'))), '/') . (is_dir(ltrim($value, '@')) ? '/' : ''));
                    }

                    if (count($data) != count($data, COUNT_RECURSIVE))
                    {
                        $data = http_build_query($data, '', '&');
                    }
                }

                curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
            }

            curl_setopt($curl, CURLOPT_CUSTOMREQUEST, strtoupper($method));

            if (isset($cookie) === true)
            {
                curl_setopt_array($curl, array_fill_keys(array(CURLOPT_COOKIEJAR, CURLOPT_COOKIEFILE), strval($cookie)));
            }

            if ((intval(ini_get('safe_mode')) == 0) && (ini_set('open_basedir', null) !== false))
            {
                curl_setopt_array($curl, array(CURLOPT_MAXREDIRS => 5, CURLOPT_FOLLOWLOCATION => true));
            }

            if (is_array($options) === true)
            {
                curl_setopt_array($curl, $options);
            }

            for ($i = 1; $i <= $retries; ++$i)
            {
                $result = curl_exec($curl);

                if (($i == $retries) || ($result !== false))
                {
                    break;
                }

                usleep(pow(2, $i - 2) * 1000000);
            }
        }

        curl_close($curl);
    }

    return $result;
}

And pass this as $cookie parameter:

$cookie_jar = tempnam('/tmp','cookie');