Re: UGLY_DEFS for darwin in configure.in

[John W. Eaton]

On  3-Oct-2007, Thomas Treichl wrote:

| With Mac's sed yes, it somehow looks the same and I was not able to fix it 
| before I've started this thread.

OK, I checked in a patch that I think will fix the problem that was
reported in the other thread.  But I see now that the Mac sed doesn't
seem to handle things like

  sed -n 's/\(THIS\|THAT\)/\1/p' < foo

as the alternation expression is not matching.  It does work if it is
rewritten like this:

  sed -n -E 's/(THIS|THAT)/\1/p' < foo

but how lame is that?  Or am I expecting too much?  What other modern
seds don't support this feature?  Is it required by POSIX?  Should we
try to work around this, or just reject a sed that doesn't work the
way we expect here?  Anyway, I guess this provides a test case we
could use to extend the OCTAVE_PROG_SED test in aclocal.m4.

jwe