php fsockopen()

<?php 
    function check_url($url){
        $url_pieces = parse_url($url);//解析url,返回数组
　　　　　//设置路径和端口
        $path = (isset($url_pieces['path']))?$url_pieces['path']:'/';
        $port = (isset($url_pieces['port']))?$url_pieces['port']:80;
        
        if (!!$fp = fsockopen($url_pieces['host'],$port,$errno,$errstr,30)){//连接
　　　　　　　//向服务器发送一些数据
            $send = "HEAD $path HTTP/1.1\r\n"; // \r\n是为了满足正确的请求格式
            $send .= "HOST:{$url_pieces['host']}\r\n";
            $send .= "CONNECT:Close\r\n\r\n";
            fwrite($fp, $send);

　　　　　　　//读应答　$data = fgets($fp, 128);
            fclose($fp);//关闭连接
            list($reponse, $code) = explode(' ', $data);
            
            if ($code == 200) {
                return array($code,'good');
            }else{
                return array($code,'bad');
            }
        }else{
            return array($errstr,'bad');
        }
    }
    
    $urls = array(
        'http://www.larryullman.com/',
        'http://www.larryullman.com/wp-admin/',
        'http://www.larryullman.com/tutorials'
    );
    
    echo '<h2>Validating URLs</h2>';
    set_time_limit(0);
    
    foreach ($urls as $url){
        list($code ,$class) = check_url($url);
        echo "<p><a href=\"$url\" taget=\"new\">$url</a>(<span class=\"$class\">$code</span>)</p>\n";
    }
?>