PHP Download Script Works But Client Browser Does Not Download - php

Question

This script is for my http file server. I have my files out of web root, so I am using a php script to grab and send the files to the client. The problem is, when I click on the file to download the browser(ff and chrome) does not ask me if I want to save the file. In chrome's web tools, under network, I see that the download.php did execute successfully. In fact, I even see where the file was transfered in bytes for the request. But the downloaded file is not on the client computer. Why isn't the browser client asking/downloading the file?
Web server is Nginx.
<?php
$path = "/trunk/";
$file = $_POST['filename'];
$file_ext = pathinfo($file, PATHINFO_EXTENSION);
$file_name = pathinfo($file, PATHINFO_BASENAME);
$file_full = $path . $file_name;
$finfo = new finfo(FILEINFO_MIME_TYPE);
$ctype = $finfo -> file($file_full);
header("Content-Disposition: attachment; filename=\"".$file_name."\"");
header("Content-Type: " .$ctype);
header("Content-Length: " .filesize($file_full));
error_log(filesize($file_full));
readfile($file_full);
?>
Request Header:
POST /php/download.php HTTP/1.1
Host: www.example.com
Connection: keep-alive
Content-Length: 146
Origin: https://www.example.com
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.79 Safari/537.4
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryMA7u5AkYPL9qGmRY
Accept: */*
Referer: https://www.example.com/index.php
Accept-Encoding: gzip,deflate,sdch
Accept-Language: en-US,en;q=0.8
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.3
RESPONSE HEADER
HTTP/1.1 200 OK
Server: nginx
Date: Sat, 01 Dec 2012 20:22:28 GMT
Content-Type: application/zip
Content-Length: 75090
Connection: keep-alive
Keep-Alive: timeout=300
X-Powered-By: PHP/5.4.6--pl0-gentoo
Content-Disposition: attachment; filename="try.zip"
Expires: Sat, 01 Dec 2012 20:22:27 GMT
Cache-Control: no-cache

Answer 1

Use Content-Type: application/octet-stream to guarantee a forced download across all browsers. If you know you are sending binary content (like your zip), then add Content-Transfer-Encoding: binary as well.