php获取远程文件大小

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