Re: automake results on OpenBSD 4.0

[Ralf Wildenhues]

Hi Eric,

* Eric Blake wrote on Wed, Jan 23, 2008 at 06:34:10PM CET:
>
> I'm not sure if grep -a is portable (POSIX doesn't require it),

AIX grep has no -a.

> so is the following patch appropriate (and should we also mention
> this in the autoconf manual)?

FWIW, as a general (hand-waving) rule, I would rather use POSIX as base
from which to document deviations, than BSD or GNU features.  That way
the Autoconf manual doesn't end up documenting all extensions as such.

> and if I were to install expect, I assume the entire test would pass.

Yes, I expect that, too (sorry for the pun).

> Eric Blake <ebb9 <at> byu.net> writes:
> > 
> > +# Check that grep can parse nonprinting characters
> > +# BSD grep can do so from a pipe, but not a file.
> 
> Maybe we should also add a line:
> +# BSD 'grep -a' does just fine from files, but 'grep -a' is not portable.

Why not, and yes, please apply the patch with this.  Thanks for the
report and analysis; confirmed, BTW.

> > -  grep ": pass" stdout | $FGREP "$grn"
> > +  cat stdout | grep ": pass" | $FGREP "$grn"
> 
> Wow - I wrote something that superficially looks like a useless use of
> cat, but which actually changes the test outcome.

If you want to add a note about that, too, feel free to.

Cheers,
Ralf