[9fans] Globbing

[lucio@proxima.alt.za]

For the record, I have no trouble agreeing with dvd, although I'm
speaking from a weak position: I have not explored all the possible
consequences of changing the globbing rules to remove duplications.

I think forsyth put his agnostic view rather well, but in my opinion
applying a uniqueness filter would be esthetically preferable.

As for consequences, here are a few data points.

* I don't think there are any advantages to retaining duplicates, they
  just clutter scripts that have to deal with them.

* It isn't always possible and it is never clean to apply filtering to
  the output of the globbing operation.  At least, to the best of my
  knowledge.  We are talking about the command line, here.  A
  particular ugly case would be

	> x*

  just to stir the pot a little further.  But of course that could be
  taken as an argument in favour of either standpoint.

* It is a change in the league of another similarly controversial
  difference between rc and the traditional Unix shells (or is it
  exec(2)?).  Lack of a leading /, ./ or ../ allows rc to use the "path"
  variable to determine the origin of an executable, whereas the
  presence of a slash anywhere in the command name suppresses this
  behaviour in traditional Unix shells.

You should have seen the confusion, consternation and outright
resentment a question on this last subject caused on a NetBSD mailing
list.  It didn't help that I used the term "absolute" to describe a
pathname starting with /, ./ or ../ and "relative" for one that
didn't.

++L

PS: One NetBSD contributor suggested making up a version of the shell
with behaviour more similar to rc's.  I refrained from pointing out
that rc was as good as I needed, in that case.