Re: Which systems have shell without functions or without unset?

[Ralf Wildenhues]

Hi Ralf,

* Ralf Corsepius wrote on Fri, Jul 01, 2005 at 02:04:07AM CEST:
> On Thu, 2005-06-30 at 14:01 +0200, Stepan Kasal wrote:
> > Hello,
> >   the autoconf manual says
> >     "You cannot assume the support of unset."
> > But no OS is mentioned.
> 
> ["unset functions '# !'" insufficiently documented]
> 
> IMO, there are good reasons for not doing so and for not given any
> OS/shell versions, because nobody really knows and nobody really needs
> to know, nor is it of much importance nowadays ... You'll very soon
> notice should you once hit an OS or a shell which doesn't ;)

Only if you put it in a high-profile software package which _is_ used on
such an OS.  Surely one might argue that if it's not used often any
more, no need to work around it.  This does move the burden to the few
users which happen to still use that OS.

I'm really not into arguing much about this topic (at least I personally
would like not to, given recent discussion elsewhere), but: if I want to
provide portable software, I prefer to be able to make a reasonable
choice about which features I should not use, and which ones I may use
safely.  For example, Libtool's use of shell function seems pretty safe
to me, while it does not use shell-local variables or `unset' (but could
make good use of either).

> However, Sven Mascheck has a pretty comprehensive overview on these
> topics on http://www.in-ulm.de/~mascheck/bourne. Unfortunately this page
> currently doesn't seem to be accessible

It is accessible again, and indeed a valuable resource, combined with
Paul Jarc's lintsh page[1] and the shell diffs page[2].  :)

Regards,
Ralf

[1] http://code.dogmap.org./lintsh/
[2] http://www.unix.org/whitepapers/shdiffs.html