Hello,

I have the code below which simply downloads a test file. It works fine if I run it as it is. However if I put this code inside a more complex page then the downloaded file contains some extra characters.

I mean to output should be a simple 1 byte file which contains a letter 'a'. However if I built in this code then the downloaded file will be 6 byte long as there are some hidden characters before 'a'.

Maybe it is relevant to character encoding but I have no idea how to fix it.

        header("Pragma: public");
        header("Expires: 0");
        header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
        header("Content-Type: application/force-download");
        header("Content-Type: application/octet-stream");
        header("Content-Type: application/download");
        header("Content-Disposition: attachment;filename=test.txt"); 
        header("Content-Transfer-Encoding: binary ");
        
        echo "a";

Any idea how can I eliminate the extra bytes?

Thanks in advance!

If you use something like the firebug net tab, and look at the answered headers from the server, what do you see ?

What is the encoding of the php file too ?
It may be that your PHP file contains a BOM (Byte Order Mark). It's a specific encoding indication that is put at the beginning of a file, but most of the time hidden to you by the editors, as they just use it to get the file encoding.

You might be able to see it if you use an hex editor, but I cannot say for sure.
Maybe something like scite , if you enable the display of the white spaces, will show it to you, I don't know.
scite: http://prdownloads.sourceforge.net/s...1.zip?download

It's been so long I have not been exposed to a BOM, that I honestly don't remember how to see it.
And I'm running a Linux desktop anyway, so...

On windows, I've found a link about a BOM detector, written in .net: http://www.wiso.cz/2007/08/08/bomdet...-bom-in-files/

Maybe it can tell you if your file does have a BOM.

Problem solved.
There were some space and new line character after the closing php tag in a file which was imported before the download.

Why do you use three different content-types in one response? Anyway only the last one will be sent to client.