使用PHP下载脚本发送正确的文件大小 [英] Sending correct file size with PHP download script

问题描述

我在PHP中创建了一个文件下载脚本，它的工作原理，但Web浏览器报告该文件为未知长度。我的代码如下：

  function downloadFile（$ file）{
 //设置下载系统。
 header（'Content-Description：File Transfer'）; 
 header（'Content-Type：'.mime_content_type（$ file））; 
 header（'Content-Disposition：attachment; filename ='。basename（$ file）。''）; 
 header（'Content-Transfer-Encoding：binary'）; 
 header（'Expires：0'）; 
 header（'Cache-Control：must-revalidate，post-check = 0，pre-check = 0'）; 
 header（'Pragma：public'）; 
 header（'Content-Length：'.filesize（$ file））; 
 
 //刷新缓存
 ob_clean（）; 
 flush（）; 
 
 //将文件发送到浏览器
 readfile（$ file）; 
 
 //不要做任何后续文件下载
退出; 
} 
  

解决方案

http://paul.luminos.nl/update/471 =nofollow noreferrer> http://paul.luminos.nl/update/471 ：

CrimsonBase网站通过将下载传递给用户PHP脚本类似于Andrew Johnson在关于PHP控制的文件下载的文章。

Andrew在文章末尾做了非常重要的评论：

如果你使用Zlib，mod_deflate等压缩文件Content-Length头部不准确，所以你会看到未知大小和

我要强调的是：如果您的浏览器似乎没有遵守你的PHP脚本生成的头文件 - 特别是 Content-Length -it很可能启用了Apache的 mod_deflate 扩展。

您可以在适用的 .htaccess 文件中使用以下行简单地禁用单个脚本：

  SetEnvIfNoCase Request_URI ^ / download\.php no-gzip dont-vary 
  pre> 
 
 
其中，download.php假设位于服务器根目录路径下的下载脚本中（例如 www.crimsonbase.com/download.php ）。 （这是因为正则表达式是 ^ / download\.php 。）
 
 

I created a file download script in PHP, it works, but web browsers report the file as "Unknown Length". My code is as follows:

function downloadFile($file){
  // Set up the download system...
  header('Content-Description: File Transfer');
  header('Content-Type: '.mime_content_type($file));
  header('Content-Disposition: attachment; filename="'.basename($file).'"');
  header('Content-Transfer-Encoding: binary');
  header('Expires: 0');
  header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
  header('Pragma: public');
  header('Content-Length: '.filesize($file));

  // Flush the cache
  ob_clean();
  flush();

  // Send file to browser
  readfile($file);

  // DO NOT DO ANYTHING AFTER FILE DOWNLOAD
  exit;
}

解决方案

Originally from http://paul.luminos.nl/update/471:

The CrimsonBase website verifies downloads by passing them through a robust PHP script similar to the one published by Andrew Johnson in his article about PHP-controlled file downloads.

Andrew makes a very important comment at the end of the article:

"If you compress files with Zlib, mod_deflate and so on the Content-Length header won't be accurate so you'll end up seeing "Unknown size" and "Unknown time remaining" when downloading files."

I would like to stress this: if your browser doesn't appear to be obeying the headers generated by your PHP script—especially Content-Length—it is fairly likely that Apache's mod_deflate extension is enabled.

You can easily disable it for a single script using the following line in an applicable .htaccess file:

SetEnvIfNoCase Request_URI ^/download\.php no-gzip dont-vary

where download.php is here assumed to be in the download script located in the server's root directory path (e.g. www.crimsonbase.com/download.php). (That's because the regular expression is ^/download\.php.)

这篇关于使用PHP下载脚本发送正确的文件大小的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！