Re: help with pattern matching needed

[Christoph Anton Mitterer]

On Sat, 2022-01-08 at 12:49 -0500, Chet Ramey wrote:
> It's not a violation. There are a couple of interpretations that
> attempt to
> clarify the distinction between "shell-quoted characters" and
> characters
> that are  quoted for the pattern. These primarily involve
> backslashes,
> since the only way to quote a pattern special character in a pattern
> is by
> using a backslash, but it applies to other shell quoting as well.
> 
> For instance, if you have
> 
> case . in
> '[.]')  echo match ;;
> *)      echo no match ;;
> esac
> 
> do you think the user's desire is to have it print `match'?

Uhm...

It's a trap! :-P

But as far as I understand now, the [.] is taken literally because of
the [ being quoted, so no match.


> > > 
> There's no missing closing bracket. dash doesn't understand $[], and
> an
> opening bracket without a matching close is not a pattern syntax
> error,
> just a string to match.
> 
> > And even stranger that (d)ash then matches [.xxxxxxxxxxxx^$[] ...
> > how
> > did you construct that?
> 
> Why is this strange? That's a valid pattern expression for dash's
> matcher
> (the backslash escapes the ending `]'). The `*' in the pattern
> matches an
> arbitrary number of `x's.

Both clear in the meantime... I forgot about [ without a closing ]
being a valid pattern.



Thanks as well,... also for the pointers to the discussion at the
Austin Group.


Chris.