PHP 获取远程文件的大小的3种方法

1、使用file_get_contents()

<?php
$file = file_get_contents($url);
echo strlen($file);
?>

2. 使用get_headers()

<?php
$header_array = get_headers($url, true);
$size = $header_array['Content-Length'];
echo $size;
?>

PS:

需要打开allow_url_fopen!
如未打开会显示
Warning: get_headers() [function.get-headers]: URL file-access is disabled in the server configuration

3.使用fsockopen()

<?php
function get_file_size($url) {
    $url = parse_url($url);
 
    if (empty($url['host'])) {
        return false;
    }
 
    $url['port'] = empty($url['post']) ? 80 : $url['post'];
    $url['path'] = empty($url['path']) ? '/' : $url['path'];
 
    $fp = fsockopen($url['host'], $url['port'], $error);
 
    if($fp) {
        fputs($fp, "GET " . $url['path'] . " HTTP/1.1
");
        fputs($fp, "Host:" . $url['host']. "

");
 
        while (!feof($fp)) {
            $str = fgets($fp);
            if (trim($str) == '') {
                break;
            }elseif(preg_match('/Content-Length:(.*)/si', $str, $arr)) {
                return trim($arr[1]);
            }
        }
        fclose ( $fp);
        return false;
    }else {
        return false;
    }
}
 
?>