W3C home > Mailing lists > Public > w3c-dist-auth@w3.org > July to September 2001

Re: WebDAV and write access discovery

From: Steinar Bang <sb@metis.no>
Date: Mon, 02 Jul 2001 16:17:16 +0200
To: w3c-dist-auth@w3.org
Message-ID: <m3lmm7o1p8.fsf@viffer.computas.no>
>>>>> Steinar Bang <sb@metis.no>:

>>>>> "Clemm, Geoff" <gclemm@rational.com>:

>> Probably the most general way to handle this is with the Expect
>> header ... that lets the server tell you that the request will fail
>> before you've sent the request body (an ACL violation is only one
>> of the reasons why the request might fail).

> Thanx for the tip.  Quick reference for other uninitiated:
> 	<http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.20>

> Basically, if I've understood section 8.2.3 on how to handle the
> 100-continue response to an expect request (link at the end of the
> above section), the client should not send the body of the message
> until it sees a "100 continue" response to the server.

> So that would avoid me having to send the body over twice, in the
> case of authentication of a PUT request, which is great.

I use libwww, so it looks like I may be using expect already:
	<http://www.w3.org/Library/src/HTTimer.html>

From the logs it looks like the body may be sent twice where
authentication is required, but that may be caused by the 2 sec
timeout being too short for slow servers.

The question is then, can I do the thing below...?

> One thing I would like to do, is to find out if a file is writable
> when I load it.  Ie. I would like to do something like:
>  - GET a file
>  - immediately start a PUT of the file with the expect header in place
>  - if I get a "100 continue" response, set the file to be R/W,
>    otherwise mark it as read-only
Received on Monday, 2 July 2001 10:17:23 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 2 June 2009 18:43:56 GMT