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Re: carriage return line endings vs. literal ^M in status.m4

From: Ralf Wildenhues
Subject: Re: carriage return line endings vs. literal ^M in status.m4
Date: Sat, 5 Apr 2008 18:24:31 +0200
User-agent: Mutt/1.5.17+20080114 (2008-01-14)

* Jim Meyering wrote on Sat, Apr 05, 2008 at 03:26:28PM CEST:
> Ralf Wildenhues <address@hidden> wrote:
> > * Jim Meyering wrote on Sat, Apr 05, 2008 at 03:08:24PM CEST:
> >>
> >> "pretty portable" may not be enough for autoconf ;-)
> >
> > It's very portable.  Really.
> (curious, not argumentative) How do you know?

Well, I certainly don't have Paul's kind of experience with unixy
shells, but working on Autoconf makes you absorb all portability
issue documents on shells you can get your eyes on, and try out all
suspicious-looking constructs on all shells you can get your fingers

The fact that redirection works on compound commands with all Bourne
shell clones is documented indirectly in
<>, where Sven mentions
that a subshell may be created.  (When it comes to traditional shells,
Sven's pages are the definite reference.)

And I think I have tried this out at some point with several modern
shells, so I'm pretty confident with those.

> >   for var in $list; do
> >     $cmds
> >   done | $cmd

> It's the same concept, sure.  But not the same syntax, and guaranteed
> not to be the same parser rule in every bourne shell's grammar.

Ah, there you give just enough rope to start nit picking.  There's only
one Bourne shell.  ;-)

And that Bourne shell's source is here:
<> and shows
quite nicely that compound commands were handled uniformly; go up the
directory for the rest of the sources, or, for a version compilable on a
modern system: <> if you prefer
trying out to reading the source; but reading is an interesting thing to
do in itself.  I suppose you remember those pre-ANSI ways of writing C a
lot better than I could.  ;-)


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