carroll@cs.uiuc.edu (Alan M. Carroll) (03/27/91)
We have a TCP connection server running on various UNIX boxes here,
and we want to be able to connect to it from a TI. In terms of
actually getting the connection and moving data on it, we have that
mostly solved. The last sticking point is that certain special
characters (primarily linefeed) are not the same on either end. The
UNIX linefeed ends up as a delta on the TI, and the TI linefeed shows
up as an ASCII 141 (cr with the high bit set). We tried using
:characters :ascii with ip:open-stream, but that maps TI linefeed into
UNIX cr / lf, and what we want is a one to one mapping, TI linefeed
<-> UNIX linefeed. Can anyone give us any clue as to the easiest way
to do this? Thanks.
--
Alan M. Carroll "I hate shopping with the reality-impaired"
Epoch Development Team - Susan
CS Grad / U of Ill @ Urbana ...{ucbvax,pur-ee,convex}!cs.uiuc.edu!carrollRice@SUMEX-AIM.STANFORD.EDU (James Rice) (03/28/91)
It sounds to me like you're trying this the hard way. The
Explorer's normal stream/file capability does this for you
for free (assuming I understand what you're trying to do).
All you need do is
(open "<<my-unix-box>>:<<my-file>>" :direction :input
:characters t)
and it will open a stream of the right type. Actually it
even defaults in to :characters t and :direction :input
anyway.
If you're trying to do anything more clever than this then
you need to know that what the Explorer actually opens,
when you do the above, is a stream of the flavor
ip:ascii-translating-character-stream. This flavor of
stream does more than frob the crlf problem, it also deals
with all of the other chars in the Explorer character set.
If you really want to do something more clever than this
then you should probably just specialize this class of
stream and open a stream of your new flavor. The easiest
way to do this (since you are overriding the way that the
generic network code deduces what sort of stream to open
for a given medium is to bind the variable
ip:*tcp-stream-instantiator*, which can be a function that
actually does a make-instance on the flavor of stream that
you want.
Rice.