Download of .zip file runs a corrupted file php

I'm trying to force a download of a protected zip file (I don't want people to access it without logging in first.

I have the function created for the login and such , but I'm running into a problem where the downloaded file is corrupting.

Here's the code I have:

$file='../downloads/'.$filename;
header("Content-type: application/zip;\n");
header("Content-Transfer-Encoding: Binary");
header("Content-length: ".filesize($file).";\n");
header("Content-disposition: attachment; filename=\"".basename($file)."\"");
readfile("$file");
exit();

Here's the error: Cannot open file: It does not appear to be a valid archive.

The file downloads fine otherwise, so it must be something I'm doing wrong with the headers.

Any ideas?

Solution 1:

This issue can have several causes. Maybe your file is not found or it can not be read and thus the file’s content is just the PHP error message. Or the HTTP header is already sent. Or you have some additional output that then corrupts your file’s content.

Try to add some error handling into your script like this:

$file='../downloads/'.$filename;
if (headers_sent()) {
    echo 'HTTP header already sent';
} else {
    if (!is_file($file)) {
        header($_SERVER['SERVER_PROTOCOL'].' 404 Not Found');
        echo 'File not found';
    } else if (!is_readable($file)) {
        header($_SERVER['SERVER_PROTOCOL'].' 403 Forbidden');
        echo 'File not readable';
    } else {
        header($_SERVER['SERVER_PROTOCOL'].' 200 OK');
        header("Content-Type: application/zip");
        header("Content-Transfer-Encoding: Binary");
        header("Content-Length: ".filesize($file));
        header("Content-Disposition: attachment; filename=\"".basename($file)."\"");
        readfile($file);
        exit;
    }
}

Solution 2:

I bet two beers that a PHP error occurs, and the error message messes up the ZIP file. The requested file probably doesn't exist.

Open the ZIP file with notepad or a similar text editor, and find out what's wrong.

Solution 3:

Late answer but maybe useful for users not being able to make force download work.
Add the following at the top of your php script

<?php
apache_setenv('no-gzip', 1);
ini_set('zlib.output_compression', 0);

Solution 4:

I had similar problems for large zip files This works for me:

In your php.ini, change to:

• Upload_max_filesize - 1500 M
• Max_input_time - 1000
• Memory_limit - 640M
• Max_execution_time - 1800
• Post_max_size - 2000 M

In your php file.

    $filename = "MyFile.zip";           
    $filepath='../downloads/'.$filename;    //your folder file path    
    header($_SERVER['SERVER_PROTOCOL'].' 200 OK');
    header("Content-Type: application/zip");
    header("Content-Transfer-Encoding: Binary");    
    header("Content-Length: ".filesize($filepath)); 
    header("Content-Disposition:attachment;filename=\"".basename($filepath)."\"");


    while (ob_get_level()) 
    {
     ob_end_clean();
     }
    readfile($filepath);   
    exit;
    ob_start ();