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Re: closure & character sets

1992-01-06 23:32:23
However, B-news and C-news had to be tweaked to allow ESCs. I don't
know about the relationship between NNTP and B,C-news (help, Henry,
Erik F.?).

NNTP is (ignoring minor complications) a protocol for transmitting
news, while B and C News are (ignoring more complications) software
for receiving, storing, and routing it.

I can't speak for B News, but neither NNTP nor C News cares whether
there are imbedded ESCs in news being passed through.  Both B and C
news normally filter out ESCs from news being posted.  (Note that in
C News at least, news arriving from another site -- having been posted
somewhere else -- and news being posted locally are very different
cases.  B News historically confused them somewhat.  Beware.)

Speaking for C News...  We pass through even the weirdest garbage
coming in from somewhere else because we don't claim to know better
than the posting site what a legitimate message is.  We filter stuff
being posted because in the normal case, the posting-site software *does*
know better than the user what a legitimate message is.  In an ASCII world
with a zillion different terminal types, ESC serves no useful purpose
in news and can foul up innocent users' terminals, and there are lots
of twits out there who think that (e.g.) all the world's a VT100.

A site which has legitimate uses for ESC can and should modify the
posting part of C News -- it is a shell script, relatively simple to
modify -- to allow ESC through.  Once ESC has gotten posted, somehow,
C News sites relaying the message onward will pass it through unchanged.
(B News historically was not so good about this, although I don't know
offhand whether ESCs in particular were affected.)

Apart from this one user-interface restriction, the usual C-derived
requirement that ASCII NUL not appear in text (which is, I think, observed
by all the new character sets), and the obvious requirement that state-
change games played in header contents not affect recognition of following
headers, to the best of our ability C News neither knows nor cares what
character set is used in text.

                                         Henry Spencer at U of Toronto Zoology
henry(_at_)zoo(_dot_)toronto(_dot_)edu   utzoo!henry

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