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To:	haahr@mv.us.adobe.com (Paul Haahr)
Cc:	rc@hawkwind.utcs.toronto.edu
Subject: Re: Differences between Duff's rc and Byron's 
Date:	Thu, 27 May 1993 01:02:11 -0400
From:	Alan Watson <alan@oldp.astro.wisc.edu>
X-Mts: smtp

> $^ is most definitely necessary.  ok, you can simulate the operation with:
> 
> ...
> 
> but the operation itself is fundamental.  the concatenation semantics just
> about require it.  (eval, for example, does flattening internally.)

Sure, and the ability to malloc is fundamental, but that doesn't mean
the user should be able to do it.  You are confusing an internal
implementation detail with an externally visible feature.  The user
need never type $^foo, although obviously rc needs to know what to do
with $foo^' '^$bar.

The only excuses for $^foo are typing convenience and speed, and I very
much doubt the later is especially noticeable.

> newpgrp on the other hand is a hack.  it's there because otherwise rc
> would be much less usable on some (admittedly broken) systems.

Educate me: why can't you use the nice, nohup, et al. approach?  I
don't understand enough of why it's there in the first place to decide
for myself.  Where do you use it -- once per login-shell, or
continually through a session, or what?

And, hey, the test command on Ultrix is broken, and rc would be much
more useable if it were built-in. :-)