// create both cURL resources
$ch1 = curl_init();
$ch2 = curl_init();

// set URL and other appropriate options
curl_setopt($ch1, CURLOPT_URL, "https://www.google.pl/");
curl_setopt($ch1, CURLOPT_HEADER, 0);
curl_setopt($ch2, CURLOPT_URL, "http://www.php.net/");
curl_setopt($ch2, CURLOPT_HEADER, 0);

//create the multiple cURL handle
$mh = curl_multi_init();

//add the two handles
curl_multi_add_handle($mh,$ch1);
curl_multi_add_handle($mh,$ch2);

$active = null;
//execute the handles
do {
    $mrc = curl_multi_exec($mh, $active);
} while ($mrc == CURLM_CALL_MULTI_PERFORM);

while ($active && $mrc == CURLM_OK) {
    if (curl_multi_select($mh) != -1) {
        do {
            $mrc = curl_multi_exec($mh, $active);
        } while ($mrc == CURLM_CALL_MULTI_PERFORM);
    }else{
        echo '.';
        sleep(1);
    }
}

//close the handles
curl_multi_remove_handle($mh, $ch1);
curl_multi_remove_handle($mh, $ch2);
curl_multi_close($mh);

while ($active && $mrc == CURLM_OK) {
    curl_multi_select($mh);
    
    do {
        $mrc = curl_multi_exec($mh, $active);
    } while ($mrc == CURLM_CALL_MULTI_PERFORM);
    
    if ($mhinfo = curl_multi_info_read($mh)) {
        $response = curl_multi_getcontent($mhinfo['handle']);
        echo PHP_EOL.'Zawartosc watku: '.$response.'####';
    }
}