🚀 go-pugleaf

On Saturday, in article
     <20120908.1856.12090103snz@i-m-t.demon.co.uk>
     v$af$ppint@i-m-t.demon.co.uk "ppint. at pplay" wrote:

>         - hi; in article, <20120905.1309.932310snz@twoplaces.co.uk>,
>           simon@twoplaces.co.uk "Simon Turner" reflected & updated:
> 
> >[...].  For the new Demon mail platform, it
> >should currently be set thus (put it in your AUTOEXEC.NET):
> >
> >  pop3 wildpat ">Received: from *[      ]by *.inty.net *[       ]for <**>*"
> 
>         - this wildcard system appears to work fine; i placed the above
>         line just before the PPP commands section, & after the NNTP com-
>         mands, but suspect this isn't critical, since a) it'll only be
>         triggered after the connection is established, and b) simon'd've
>         warned if it were - unless he's possessed of a sense of humour
>         most perfectly suited to the denizens of afp or alt.sex.reptiles...

8-)  As you found, since this is a POP3 setup command, it can go
wherever you like, as its settings won't be looked at until the first
time you issue "pop3 collect".

(And it can be redefined whenever you like, in case you ever find
yourself having to collect POP3 mail from more than one account where
they indicate the recipient in different ways: you could have a series
of script files, each one containing "pop3 wildpat" followed by "pop3
collect", and "source" each script in turn.)

>         [...](t'other was that
>         "leave on" after collection proved to be the default, which i
>         didn't discover 'til the second time i connected & collected:
>         but this wasn't pplt_03e's fault, and was fixed on the follow-
>         ing connection by a guessed-at command, pop3 leave off<enter>
>         from the net> prompt.)(well, it _seems_ to've worked...)

This puzzles me mightily, as "pop3 leave" has always defaulted to off;
unless you've got something somewhere that turns it on, you shouldn't
need to explicitly turn it off.  Let me know if it recurs!

> >The stuff in the two pairs of square brackets [ ] is a space (ASCII 32)
> >and a tab (ASCII 9) -- check this carefully if you cut-and-paste the
> >line from this article, because if you don't have the tab character in
> >there, the pattern won't match the header fields created by the new
> >platform.  (The space is belt-and-braces, in case they decide to stop
> >using tabs and revert to the spaces that every other server uses.)
> 
>         - what happens if they decide to insert comments?  (- [a])

[a] noted; but taking it seriously, theoretically they could, although I
doubt anyone would be so silly.  But so long as the comments didn't
appear in between "by" and "*.inty.net", or between "for" and the
recipient address -- which, if they did, would break every parser on the
planet -- the existing pattern would continue to work; and if it did
stop working, it would be a simple matter to adjust it for the new
circumstances.

> >A quick explanation of the unusual bits of this wildcard pattern:
> >
> > * The ">" at the beginning tells it to use the *last* match found
> >   rather than the first; when using the catch-all administrator
> >   mailbox, all the "Received:" fields except the last contain
> >   administrator@yourhost which isn't a lot of help.  (Turnpike falls
> >   foul of this.)
> >
> > * The unusual "**" near the end tells GremNOS which part of the pattern
> >   contains the actual address it's trying to find.
> 
>         - how long would it take me to learn the hows & whys of how
>         & why the above makes sense?  & is it o.k. if i just *gulp*,
>         and say "yes, simon, certainly, simon"/"of course, simon" ?

The latter option is probably the best course!  They are both wildly
non-standard extensions to wildcard matching, invented by me just for
this purpose, and will not work outside GremNOS.

For the curious: with Demon's inserted "Received:" fields all looking
the same, with only the last one reliably containing the actual
recipient address rather than "... for <administrator@yourhost>", I
needed a mechanism to indicate that the pattern should continue to be
used even after a match had been found (normally it will stop searching
after finding a match).  No header fields start with ">", so I chose
that.

The "**" is because the pattern will generally (as in this case) contain
more than one "*" (matching an arbitrary length of any text), and I
needed something to tell GremNOS which one was the important one!  "**"
is meaningless in wildcard matching, so I chose that.  (It *should*
probably be harmless if it ever got used as part of a "live" pattern.)

GremNOS internally parses and rewrites the provided pattern into a
normal one (removing the ">" and rewriting "**" to "*", once it has
counted which instance of "*" it is) at the start of "pop3 collect".

-- 
Simon Turner                                    DoD #0461
simon@twoplaces.co.uk
    Trust me -- I know what I'm doing!          -- Sledge Hammer