Force download corrupts ZIP file

[kristo5747]

I wrote a very simple web form that allows my user to view text files from within their Internet browser.

 

I implemented a feature whereby the text files returned by the search are compressed into a ZIP. Here's my code

            function getFiles() {
             $result = null;
             $ZIPresult = null;
             if (empty($_POST['DBRIDs'])) { return null; }
             $mydir = MYDIR; 
             $dir = opendir($mydir);
             $DBRIDs = $_POST['DBRIDs'];
             $getfilename = mysql_query("select filename from search_table where rid in (" . $DBRIDs . ")") or die(mysql_error());
             while ($row = mysql_fetch_array($getfilename)) {
             $filename = $row['filename'];
             $result .= '<tr><td><a href="' . basename($mydir) . '/' . $filename . '" target="_blank">' . $filename . '</a></td></tr>';
             $ZIPresult .= basename($mydir) . '/' . $filename;
            } 
            if ($result) {
            $result = "<table><tbody><tr><td>Search Results.</td></tr> $result</table>";
           shell_exec("zip -9 SearchResult.zip ". $ZIPresult ." > /dev/null ");
    
    $fileName = 'SearchResult.zip';
    header("Cache-Control: public");
    header("Content-Description: File Transfer");
    header("Content-Transfer-Encoding: binary");
    header('Content-type: application/zip');
    header("Content-length: " . filesize($fileName));
    header('Content-Disposition: attachment; filename="' . $fileName . '"');
    readfile($fileName); 
            } return $result;
            }

 

 

It works great If I download the ZIP file from the server using FTP (for example) but I force the download from the page header, the ZIP is corrupted.

 

What am I missing? Thanks for your input.

**PS: The new ZipArchive() library/class is not available on our production environment so I chose to use the Unix utility ZIP instead.**

[kicken]

If your going to try and have that page output a zip file for download, then you have to ensure it does not output anything else.  No HTML, no extra space, nothing.  The only thing it can output is the zip file.

 

 

[kristo5747]

It was an encoding problem. Tried the following:

 

ob_start(); // Starts output buffering.
readfile($fileName); // "Outputs" the file.
$content = ob_get_clean(); // Grabs the output and assigns it to a variable.
print base64_encode($content); // Encodes and prints the content to the browser.

 

Took care of it.