<?php
function getFileSize($url){
$url = parse_url($url);
if($fp = @fsockopen($url['host'],empty($url['port'])?80:$url['port'],$error)){
fputs($fp,"GET".(empty($url['path'])?'/':$url['path'])." HTTP/1.1\r\n");
fputs($fp,"Host:$url[host]\r\n\r\n");
while(!feof($fp)){
$tmp = fgets($fp);
if(trim($tmp) == ''){
break;
}else if(preg_match('/Content-Length:(.*)/si',$tmp,$arr)){
return trim($arr[1]);
}
}
return null;
}else{
return null;
}
}

echo getFileSize("http://wpa.qq.com/pa?p=2:931751994:41&r=1368852898");
?>

function getrFSize($url){
	$ui=parse_url($url);
	if(!$fh=@get_headers($url))
		return 0;
	$fs=0;
	foreach($fh as $k=>$v){
		if(preg_match('/Location:(.*)/is',$v,$matches)){
			$matches[1]=trim($matches[1]);
			if($matches[1][0]=='/'){
				$nu="http://{$ui['host']}{$matches[1]}";
			}elseif(preg_match('~^http://~is',$matches[1])){
				$nu=$matches[1];
			}else{
				$ui['path']=dirname($ui['path']);
				$nu="http://{$ui['host']}{$ui['path']}/{$matches[1]}";
			}
			return getFSize($nu);
		}elseif(preg_match('/Content-Length:(.*)/is',$v,$matches)){
			$fs=intval(trim($matches[1]));
		}
	}
	return $fs;
}