[TUHS] cat -v and other complaints

Norman Wilson norman at oclsc.org
Fri Sep 7 06:29:36 AEST 2018

Andy Kosela:

  One still cannot ignore the fact that Unix and Plan 9 offer two
  completely different approaches to displaying text.

I admit I've never actually used Plan 9.  Can you elaborate on
the different approaches?

One difference from most of what passes for UNIX these days is
probably that the basic terminal model allows one to edit anything
on the screen, using the mouse and keyboard and a simple button-2
menu similar to that of sam.  You can edit what some program has
already printed, then pick it up and send it back as input.  You
can even edit text in the current line that hasn't been sent yet
(because you haven't hit a return yet); in effect the canonical-line
part of the tty driver is in the terminal.

But you probably don't mean that, both because it's not really
such a radical difference, and because it doesn't conflict at all
with UNIX.  In fact it originated on UNIX, five or six years before
Plan 9 was thought of: it's the model from the terminal program
in mux, the more-advanced version of the Blit/Jerq window manager
that nearly everybody used in 1127 by the time I arrived in 1984.

And I still use it every day, even on Linux (and in years past
on Solaris and IRIX and Digital UNIX and Ultrix).  The modern
version of the program to do that is called 9term.  It doesn't
work quite as well as I'd like on Linux due to changes in the
tty driver that make it hard for a program to learn right away
when tty modes are changed (in particular when echo is turned off
or on), and it does conflict with the GNU readline junk because
that turns off canonical processing, but to those of us who have
a taste for it it's still just fine.

As I say, I don't think that's the difference you mean, so please
step in and supersede me.

(And feel free to use my referring to something that is part of
the latter-day Research editions as an excuse to continue discussing
it.  I think of Plan 9 as a successor to those systems anyway, and
therefore related to UNIX heritage, at least as long as we're
comparing and contrasting the systems.)

Norman Wilson
Toronto ON

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