Xref: utzoo comp.sys.3b1:468 comp.sys.att:11879 unix-pc.general:7537
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!think.com!mintaka!spdcc!gnosys!gst
From: gst@gnosys.svle.ma.us (Gary S. Trujillo)
Newsgroups: comp.sys.3b1,comp.sys.att,unix-pc.general
Subject: Re: ".GIF" files
Message-ID: <996@gnosys.svle.ma.us>
Date: 24 Feb 91 06:44:07 GMT
References: <1991Feb6.215717.26551@cbnewsj.att.com> <1991Feb7.204039.5842@sonyd1.Broadcast.Sony.COM> <993@gnosys.svle.ma.us> <843@argon.UUCP>
Organization: gst's 3B1 - Somerville, Massachusetts
Lines: 38

In <843@argon.UUCP> ebh@argon.UUCP (Ed Horch) writes:

...

> >	cat a | b | c
> >
> >is entirely equivalent in result to:
> >
> >	b < a | c

(And, as Bruce Lilly recently observed, it's also equivalent to

	< a b | c

which David might like better, since it preserves his left-to-right
ordering.

...

> There may be a performance cost due to creating an additional
> process for "cat a", but a smart shell will know how to short-
> cut around that.

I guess it was the performance cost that concerned me most - it just
requires an extra process and takes system buffers unnecessarily.
What's this about a "smart shell"?  I've never heard of a shell that
optimizes commands.  It seems inherantly very difficult to recognize
that the two commands listed above are equivalent, since it requires
a knowledge of what cat(1) does.  What shell are we talking about here?

Actually, this discussion probably doesn't belong in the unix-pc news-
groups, but I appreciate everyone's tolerance.  And now we return you
to your regular programming...  :-)

Gary
-- 
    Gary S. Trujillo                            gst@gnosys.svle.ma.us
Somerville, Massachusetts              {wjh12,bu.edu,spdcc,ima,cdp}!gnosys!gst


Brought to you by Super Global Mega Corp .com