Re: [Gnu-arch-users] back-building pfs updates

[Robert Collins]

On Sun, 2004-02-22 at 09:39, Florian Weimer wrote:
> Aaron Bentley wrote:
> 
> > > HTTP HEAD should provide the necessary information, once you have the
> > > file name.
> > 
> > Content-Length?
> 
> Yes.
> 
> > 1. Not the same as file size-- it's the size after encodings have been
> > performed
> 
> If a transfer encoding is applied, no Content-Length: header must be
> sent.

That said, Content-Encodings can and will screw this up - unless you specify 
what you will accept.

> You don't want to perform any encoding for plain files anyway.  It just
> kills server performance.

> > 3. It appears that for a HEAD request, the content-length is 0.  Can
> > anyone confirm or deny?
> 
> This looks like a server bug (it's a violation of a SHOULD in the RFC).

not at all: from 9.2
If no response body is included, the response MUST include a
Content-Length field with a field-value of "0".

yet...
9.4 HEAD

   The HEAD method is identical to GET except that the server MUST NOT
   return a message-body in the response. The metainformation contained
   in the HTTP headers in response to a HEAD request SHOULD be identical
   to the information sent in response to a GET request. 

HTTP has many such inconsistencies. It's not surprising the implementations are 
inconsistent.

A reliable way to get the real length in octects is to request bytes
0-0.

Rob

-- 
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