PHP获取远程web服务器时间的代码

<?php   
function get_time($server){   
    $data  = "HEAD / HTTP/1.1\r\n";   
    $data .= "Host: $server\r\n";   
    $data .= "Connection: Close\r\n\r\n";   
    $fp = fsockopen($server, 80);   
    fputs($fp, $data);   
    $resp = '';   
    while ($fp && !feof($fp))   
        $resp .= fread($fp, 1024);   
    preg_match('/^Date: (.*)$/mi',$resp,$matches);   
    return strtotime($matches[1]);   
}   
echo date('Y-m-d H:i:s',get_time("www.163.com"));   
?>