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Re: to conditionally test, or not to conditionally test?
From: |
Stepan Kasal |
Subject: |
Re: to conditionally test, or not to conditionally test? |
Date: |
Fri, 27 May 2005 16:04:08 +0200 |
User-agent: |
Mutt/1.4.1i |
Hi,
On Fri, May 27, 2005 at 01:38:28PM +0100, Keith MARSHALL wrote:
> > #! /usr/bin/perl
> >
> > If you omit the space before the path, then 4.2BSD based systems
> > (such as DYNIX) will ignore the line, because they interpret `#! /'
> > as a 4-byte magic number.
>
> I recently queried this advice, in respect of its application in the
> groff project, and was advised that it is nonsense. I posted that
> response here, but as yet have seen no comment.
I saw your mail and I want to comment out this paragraph, if Paul agrees.
But let's define what ``nonsense'' means:
The advice perhaps used to be true, prehaps 4.2BSD and DYNIX really had
this limitation, I don't know. But the reason to delete the advice is that
these systems are now so rare that Autoconf doesn't want to target them.
> > A real fix will be to use shell functions to reimplement AC_REQUIRE,
> > in autoconf-3.
>
> Are you now saying that shell functions are safe to use in a portable
> fashion?
Autoconf-2.x supports sustems with shells without functions. That's why
autoconf generated macros cannot use functions.
If I understood correctly what Paul said some time ago, we'll probably
drop this support in Autoconf-3. That means that Autoconf-3 will be
able to use functions internally.
But you can use functions in your configure.ac with Autoconf-2.x, if
_you_ don't need support for platforms without shell functions.
(Ralf has explained this much better.)
Hope this explains it.
Stepan
- to conditionally test, or not to conditionally test?, Ed Hartnett, 2005/05/20
- Re: to conditionally test, or not to conditionally test?, Ralf Wildenhues, 2005/05/25
- Re: to conditionally test, or not to conditionally test?, Stepan Kasal, 2005/05/26
- Re: to conditionally test, or not to conditionally test?, Ralf Corsepius, 2005/05/27
- Re: to conditionally test, or not to conditionally test?, Stepan Kasal, 2005/05/27
- Re: to conditionally test, or not to conditionally test?, Ralf Corsepius, 2005/05/27
- Re: to conditionally test, or not to conditionally test?, Stepan Kasal, 2005/05/27