[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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


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 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.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]