On 16/07/2021 10:42, Dimitar Yurukov wrote:
While parsing bracket expression ('[...]'), DASH recognizes only '!' as
a special character for negation/inversion, but POSIX specifies '^'.
The POSIX specification (2018 edition) states:
^ The <circumflex> shall signify a non-matching list expression when
it occurs first in a list, immediately following a
<left-square-bracket> (see RE Bracket Expression).
It also states:
the <exclamation-mark> character ( '!' ) shall replace the
<circumflex> character ( '^' ) in its role in a non-matching list in the
regular expression notation
and
A bracket expression starting with an unquoted <circumflex> character
produces unspecified results.
See 2.13.1 Patterns Matching a Single Character.
So both the dash and the bash behaviour are permitted and this patch
does not address a correctness issue. Scripts that rely on ^ for
negation should be modified to use !.
The patch may still be worthwhile to increase compatibility, but in that
case the same change also needs to be made to expmeta().
Cheers,
Harald van Dijk
