Re: Downloading strangeness: downloaded file has no content

On 01 Oct 2022 at 17:57:19 BST, Jerry Stuckle <[email protected]> wrote:

> On 10/1/2022 10:50 AM, Tim Streater wrote:
>> For those requesting that a file be downloaded from my website, having
>> selected a file (a .zip or a .dmg), the following is then executed:
>> 
>> <font color="#000000">header('Content-Description: File Transfer');</font>
>> header('Content-Type: application/octet-stream');
>> header('Content-Disposition: attachment; filename="' . basename ($file) .
>> '"');
>> header('Content-Transfer-Encoding: binary');
>> header('Expires: 0');
>> header('Cache-Control: no-cache, must-revalidate, post-check=0, pre-check=0');
>> header('Pragma: public');
>> header('Content-Length: ' . filesize ($file));
>> 
>> ob_clean ();
>> flush ();
>> readfile ($file);
>> 
>> 
>> For most of the files to be downloaded, this works just fine. But for one of
>> them, the downloaded file has zero content at the receiver's end: it is zero
>> bytes long. The file on the server is correct - I can download it using an FTP
>> client and drag/drop the file off the server and onto my desktop. Then it has
>> the correct size/content.
>> 
>> Any suggestions as to why this might be?
> 
> Tim,
> 
> What's in your PHP error log?  It's always the first place I check when
> I have weird problems.

Good question. I'll have to get on to the hosting provider or see whether with
the tools I have access to, I can locate it. I was minded to contact them
anyway, in case there's some file caching issue that requires a restart of
whatever VM they're running for me.

> Have you checked the contents of $file?  Is it correct - including the
> path?  What is the result of filesize($file)?

I log these items just before the first header is sent and they are as
expected. Filesize is 131Mbytes (not easily overlooked).

> What are the ownership
> and permissions on the file?  Does the web server have read access to it?

This is worth checking too, no doubt about it. :-)

-- 
"... you must remember that if you're trying to propagate a creed of poverty, gentleness and tolerance,  you need a very rich, powerful, authoritarian organisation to do it."             - Vice-Pope Eric