Re: [PATCH] Add an XSI replacement for func_split_short_opt.

[Ralf Wildenhues]

* Gary V. Vaughan wrote on Tue, Jun 29, 2010 at 08:30:43PM CEST:
> On 30 Jun 2010, at 01:22, Ralf Wildenhues wrote:
> > I think m4sh can simply use code like
> > 
> >  if ( eval '$smart_works' ) >/dev/null 2>&1; then
> >    func_foo () { smart code; }
> >  else
> >    func_foo () { safe code; }
> >  fi
> > 
> > for code run a handful of times, without need for extra m4 magic, it's
> > just that libtool is easily run hundreds of times in a typical large
> > software build so it warrants optimization.
> 
> In that case might the retarded shell choke and die as it parses 'smart
> code;'?

Good point.  IIRC gnulib-tool uses e.g.,
  eval 'func_foo () { smart code; }'

or eval inside the smart code, to get around that where needed.

> I don't actually know whether retarded shells mostly ignore the code
> during parsing, and can be reliably fed what they would otherwise consider
> garbage as long they are never instructed to execute the garbage... but
> it seems like something we'd need to be very careful about.

Just trying it with Solaris sh and maybe a couple of the other vendor
systems helps, these things are easily sorted out with your level of
system access.

Cheers,
Ralf