[NNTP] [2506] 6xx response codes

Andrew - Supernews andrew at supernews.net
Mon Nov 29 08:33:43 PST 2004


>>>>> "Clive" == Clive D W Feather <clive at demon.net> writes:

 Clive> Issue: appendix A says that 6xx response codes should be used
 Clive> for new multi-line responses. Do we do this or drop the
 Clive> appendix?

Drop it.

 >> 2506: I don't see the point of a new 6xx response.  How would a
 >> client ever find itself in such a situation?  All existing
 >> commands have well defined responses, so the client MUST know when
 >> to expect a multi-line response.  If the client gets an unexpected
 >> multi-line response, then it probably issued a command that it
 >> doesn't support, and gets what it deserves.

 Clive> You're assuming that the results parsing is tied in tightly
 Clive> with the bit of code that issues the specific command.

It is not possible, with the protocol as it stands, to parse the
results of a command without knowing which command was issued. This is
an unfortunate wart, but it's not fixable without breaking backward
compatibility for LISTGROUP, which _is_ used reasonably widely by
clients.

In practice, the pseudo-code for clients is more usually along the
lines of:

    sprintf(command, "ARTICLE %s", message-id);
    response_code = issue_command_multiline(command);
    if response_code is 2xx then process the multiline response...

-- 
Andrew, Supernews
http://www.supernews.com




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