Re: Link checking (only)

Jeff de la Beaujardiere (delabeau@iniki.gsfc.nasa.gov)
Tue, 13 May 1997 08:38:30 -0400


Date: Tue, 13 May 1997 08:38:30 -0400
Message-Id: <199705131238.IAA16753@iniki.gsfc.nasa.gov>
From: Jeff de la Beaujardiere <delabeau@iniki.gsfc.nasa.gov>
To: walter@natural-innovations.com
CC: www-html@w3.org
In-reply-to: <v03102806af9d3f11850b@[205.149.180.135]> (message from Walter
Subject: Re: Link checking (only)


Walter Ian Kaye writes:
> Telnet access... cool. (How many service types does telnet work with?)  Is
> HEAD guaranteed to not cause a "hit" on page counters?

HEAD will cause an entry in the access log file, just like GET:
  128.183.250.37 - - [13/May/1997:08:31:46 -0400] "HEAD / HTTP/1.0" 200 -
It is up to the particular page counter to ignore those if it wishes.

> I guess what I was really looking for was something like what my
> news-reader has, a "Get Server Info" command which returns a list of
> supported commands.

The OPTIONS method in HTTP/1.1 "represents a request for information about
the communication options available... This method allows the client to
determine the options and/or requirements associated with a resource, or the
capabilities of a server, without implying a resource action or initiating a
resource retrieval."  (From Sec.9.2 of
http://www.w3.org/pub/WWW/Protocols/rfc2068/rfc2068).  I don't believe
HTTP/1.0 has equivalent functionality.

> I suppose I'm just trying to gauge how much error checking an HTTP client
> would have to do (I'm planning to write one).

The HTTP/1.1 specification (RFC 2068) at the aforementioned URL will
indicate everything your user agent MUST, MUST NOT, SHOULD, SHOULD NOT, and
MAY [sic] do or expect.

--Jeff dLB

  = J-F Pitot de La Beaujardiere
  = delabeau@iniki.gsfc.nasa.gov
  = http://globe2.gsfc.nasa.gov/