php获取远程文件的大小

<p>/*</p>**功能:获取远程文件的大小,返回值的单位是:字节<br />*/<br />function get_fileSize($url){<br />	if(!isset($url)||trim($url)==''){<br />		return '';<br />	}<br />	ob_start();<br />	$ch=curl_init($url);<br />	curl_setopt($ch,CURLOPT_HEADER,1);<br />	curl_setopt($ch,CURLOPT_NOBODY,1);<br />	$okay=curl_exec($ch);<br />	curl_close($ch);<br />	$head=ob_get_contents();<br />	ob_end_clean();<br />	$regex='/Content-Length:\s([0-9].+?)\s/';<br />	$count=preg_match($regex,$head,$matches);<br />	return isset($matches[1])&&is_numeric($matches[1])?$matches[1]:'';<br />}