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Date:	Thu, 27 May 1993 02:48:33 -0400
From:	haahr@mv.us.adobe.com (Paul Haahr)
Message-Id: <9305270648.AA05256@astro.mv.us.adobe.com>
To:	alan@oldp.astro.wisc.edu
Subject: Re: Differences between Duff's rc and Byron's
Cc:	rc@hawkwind.utcs.toronto.edu

> The user
> need never type $^foo, although obviously rc needs to know what to do
> with $foo^' '^$bar.

why?  all of rc's concatenation can be written in terms of loops.
there's nothing magic about them (unlike ~ which can't be written
as a function, due to the fact that one of its arguments isn't
globbed).  they are purely there for convenience, too.

> 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 did something like this for a while.  $SHELL was a wrapper which did
the newpgrp, set SHELL to rc, and exec'ed rc.  worked, until i needed
$SHELL in that context not to create a new pgrp for some other purpose.

from my perspective, a processes' pgrp is similar to its signals, limits,
etc.  the shell manages those, so its not unreasonable for it to manage
the pgrp if it manages those other things.

> 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?

once per window, in my fn prompt.  if not, control-c in one window
sends sigint to all the terminal windows.  the vendor never noticed
this since they assumed that all shells were like csh and did their
own pgrp manipulation.

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

supply your own /usr/local/bin/test, if you really like test's semantics.
or supply something better.

paul