php4如何获取远程文件大小类

if(!function_exists('get_headers'))
{
function get_headers($url,$format=0)
{
$url=parse_url($url);
$end = " ";
$fp = fsockopen($url['host'], (empty($url['port'])?80:$url['port']), $errno, $errstr, 30);
if ($fp)
{
$out = "get / http/1.1 ";
$out .= "host: ".$url['host']." ";
$out .= "connection: close ";
$var = '';
fwrite($fp, $out);
while (!feof($fp))
{
$var.=fgets($fp, 1280);
if(strpos($var,$end))
break;
}
fclose($fp);

$var=preg_replace("/ .*$/",'',$var);
$var=explode(" ",$var);
if($format)
{
foreach($var as $i)
{
if(preg_match('/^([a-za-z -]+): +(.*)$/',$i,$parts))
$v[$parts[1]]=$parts[2];
}
return $v;
}
else
return $var;
}
}
}