[thelist] File delivery system?

kasimir-k kasimir.k.lists at gmail.com
Sat Mar 24 10:03:39 CDT 2007

> On Fri, Mar 23, 2007 at 09:50:31PM +0000, kasimir-k wrote:
>> http://php.net/connection-aborted

Bill Moseley scribeva in 24/03/2007 1:03:
> That tells you if the connection to your machine was broken.  It
> doesn't tell you if the user downloaded the file completely and it is
> now saved on their disk.

I would have thought that if the connection is still open after the file
has been output to the client, then I could be pretty sure that the
client has received the file.

> Are you sure there isn't a proxy sucking up the file and closing the
> connection before the download completes?

And the proxy would keep the file to itself and not pass it on to the
client? Is this really possible?

> Not sure what the plan is but a proxy might throw on a Vary header and
> trigger this: http://support.microsoft.com/?kbid=824847

On that page it reads "This problem is known to occur with HTML Help
files (.chm files) and vCard files (.vcf files). " - so serving other
files this wouldn't be a problem. Also the page says "you may receive
the following error message when you click the link and then click Open"
- so this wouldn't apply to downloading the file, only opening.

And after reading
I'm under the impression that the server sends this to the client, and a
proxy shouldn't add this on its own.

And if we are interested in controlling the downloads of the file, I
think it would make sense to make the file uncacheable - then we
wouldn't even need the Vary header, right?

> I think the safe bet is to allow the download over some period of time
> -- or maybe even ask the user "Click here if you received the file"
> kind of thing.

But if the idea is to limit the number of downloads, then both of these
approaches fail - the user could download the file many times over the
given period, and reply "no" to the question.


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