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To:	John (Most modern computers would break if you stood on them) Mackin <john@
	civil.su.oz.au>
Subject: Re: here strings 
Cc:	rc@hawkwind.utcs.toronto.edu
Date:	Sat, 5 Jun 1993 12:42:48 -0400
From:	Alan Watson <alan@oldp.astro.wisc.edu>
X-Mts: smtp

Sorry, John, but I'm not convinced by your example, although there may
be something I have missed.

The precise behaviour of your example can be reproduced by:

   for ( f in * ) mv $f `{ echo -n $f | tr A-Z a-z }

assuming echo is built-in (or an external, non-SYSV echo).  I strongly
suspect that your here-string solution is not very much faster than
this one, if echo is a built-in command.  So, I would tentatively class
your idiom as a speed hack on a system without a built-in echo (like
some of the means of getting at the file system through the globber and
builtin cd).

As I see it, the justification for here-strings is that echo is not a
necessarily available as a built-in, and so one cannot reliably convert
a here-document to a a series of echoes.