Re: help with pattern matching needed

[Kerin Millar]

On Wed, 12 Jan 2022 15:36:05 +0100
Christoph Anton Mitterer <calestyo@scientia.org> wrote:

> On Wed, 2022-01-12 at 07:38 -0500, Greg Wooledge wrote:
> > The quotes are irrelevant; you should get the same results if you
> > remove them.
> > 
> > POSIX only specifies ! as the negation character for [...] ranges in
> > globs.
> > Some shells also permit ^ to be used, for the comfort of people who
> > are
> > used to regular expressions.  Bash is one of the shells that permit
> > ^.
> 
> But doesn't POSIX explicitly say:
> "A bracket expression starting with an unquoted <circumflex> character
> produces unspecified results."
> 
> Which I'd interpret as also meaning that a quoted ^ is not allowed
> produce unspecified results?

Naturally. A quoted circumflex would constitute a literal circumflex in exactly 
the same way that a quoted exclamation mark would constitute a literal 
exclamation mark.

$ touch '!' a b
$ echo [!b]
! a
$ echo ['!'b]
! b
$ echo [\!b]
! b

-- 
Kerin Millar