php 获取远程文件大小

以下实例使用php curl 来获取远程文件大小 返回文件大小单位为字节：

<?php// 获取远程文件大小函数function remote_filesize($url, $user = "", $pw = ""){    ob_start();    $ch = curl_init($url);    curl_setopt($ch, CURLOPT_HEADER, 1);    curl_setopt($ch, CURLOPT_NOBODY, 1);     if(!empty($user) && !empty($pw))    {        $headers = array('Authorization: Basic ' . base64_encode("$user:$pw"));        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);    }     $ok = curl_exec($ch);    curl_close($ch);    $head = ob_get_contents();    ob_end_clean();     $regex = '/Content-Length:([0-9].+?)/';    $count = preg_match($regex, $head, $matches);     return isset($matches[1]) ? $matches[1] . " 字节" : "unknown";}// 实例测试echo remote_filesize("/assets/img/facesoho-logo@2x.png");?>

以上实例输出结果为：

8416 字节