Do cURL request to some API with cookie parsing

api.test.php

/**
 * @desc Do cURL request to some API
 * @author Misha M.-Kupriyanov https://plus.google.com/104512463398531242371/
 * @link https://gist.github.com/5055906
 */

$currentSID = null;
$SESSION_NAME = '<PUT_YOUR_SESSION_NAME_HERE>';
$API_KEY = '<PUT_YOUR_API_KEY_HERE>';
$API_URL = 'http://host/api/v1/?alt=json'


$params = array(
     $SESSION_NAME => $currentSID,
    'apikey' => $API_KEY,
    'method' => 'api.checkLoginStatus'
);

$result = doPostCall($API_URL, $params);
echo 'RESPONSE:' . print_r($result, true);

/*
 * get current SessionID
 */
$currentSID = $result['cookies'][$SESSION_NAME];
echo '$currentSID:'.$currentSID.PHP_EOL;



function doPostCall($API_URL, $fields)
{
    $fields_string = null;
    print_r($fields);

    //url-ify the data for the POST
    foreach ($fields as $key => $value) {
        $fields_string .= $key . '=' . $value . '&';
    }
    rtrim($fields_string, '&');

    echo 'URL:' . $url . PHP_EOL;
    echo 'POST:' . $fields_string . PHP_EOL;

    //open connection
    $ch = curl_init($url);

    //set the url, number of POST vars, POST data
    //curl_setopt($ch,CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST, count($fields));
    curl_setopt($ch, CURLOPT_POSTFIELDS, $fields_string);
    curl_setopt($ch, CURLOPT_HEADER, 1);
    curl_setopt($ch, CURLINFO_HEADER_OUT, 1);
    $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);

    //execute post
    ob_start();
    $postResult = curl_exec($ch);
    $return = ob_get_contents();
    ob_end_clean();

    /*
     * parse cookies
     */
    preg_match('/^Set-Cookie:\s*([^;]*)/mi', $return, $m);
    $returnArr['cookies'] = array();
    if (count($m[1])) {
        parse_str($m[1], $returnArr['cookies']);
    }

    /*
     * get response
     */
    $header_size = curl_getinfo($ch,CURLINFO_HEADER_SIZE);
    $returnArr['response'] = substr( $return, $header_size);

    if (curl_errno($ch)) {
        echo curl_error($ch) . PHP_EOL;
        echo 'Unable to do request' . PHP_EOL;
        return;
    }


    //close connection
    curl_close($ch);

    return $returnArr;
}