Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!mimsy!umd5!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.unix.wizards
Subject: Re: SysV shell questions
Message-ID: <6330@brl-smoke.ARPA>
Date: Sun, 23-Aug-87 02:51:11 EDT
Article-I.D.: brl-smok.6330
Posted: Sun Aug 23 02:51:11 1987
Date-Received: Sun, 23-Aug-87 21:48:45 EDT
References: <10279@orchid.waterloo.edu> <5980007@hpfcdc.HP.COM>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 41

In article <5980007@hpfcdc.HP.COM> rml@hpfcdc.HP.COM (Bob Lenk) writes:
>The big problem is still the cost of phase II for System III and V based
>systems.

I didn't say how long Phase 2 would have to last.  If there is going
to be a merged "echo" with semantics the application developer can
count on common to both Berkeley- and System V- based environments,
obviously at some point all uses of echo in one environment or the
other will HAVE to be revised.  That's what a transition plan is for.

The original Bell Labs "echo" did not "interpret" its arguments
(i.e. map escape sequences).  The PWB folks who added that feature
botched it when they provided no way to disable the interpretation.
Therefore it is quite fair for that camp to be the one that has to
do the work eventually.  (Note that I am often accused of being in
that camp myself.)

My proposal for -n and -e has already been implemented in 8th Edition
UNIX (except possibly for reserving all other - options), and I've
spread it around a bit in the BRL UNIX System V emulation for 4.nBSD
and in the support that can be optionally built into the native
4.nBSD version (actually, any version) of our fancy Bourne shell.

Technically one could indeed add yet another flag defined to mean
"definitely don't interpret escapes", although I don't really think
it helps -- portable applications would STILL have to change to meet
the "echo" standard, and by not specifying the default behavior you
would force ALL existing use of "echo" to be changed (at least, if
one is concerned about portability), not just one camp's.

Using environment variables for stuff like this is just too yucky!

If you understand the design principles behind the UNIX environment,
it should be obvious that plain, unadorned "echo" should do the
semantically simplest thing, namely no escape interpretation.
That is consistent with what I propose but not with System V's
current behavior.  I was hoping that IEEE 1003.2 would straighten
out a lot of the featurefulness that has infected basic UNIX
utilities over the years, rather than bless it.  It would behoove
them to study a 9th Edition UNIX Programmer's Manual, then try to
improve on it.