Non-blocking background HTTP request

async_request.php

<?php

    function async_request($url) {
        $request = parse_url($url);
        if (!isset($request['port'])) {
            $request['port'] = 80;
        }    
        $fp = @fsockopen($request['host'], $request['port'], $errno, $errstr, 30);
        if ($fp) {
            fwrite($fp, implode("\r\n", array(
                sprintf('GET %s HTTP/1.1', $request['path']),
                sprintf('Host: %s', $request['host']),
                'Connection: Close'
            )) . "\r\n\r\n");
            fclose($fp);
            return true;
        } else {
            return false;
        }
    }

?>