Re: Dealing with character ranges in grep

[Aharon Robbins]

Hi All.

This note is really encouraging - I was unaware of this change in the
latest standard.  I will be revising gawk and its documentation to reflect
this, including the links Paul has supplied.

I have not been following the details of the rest of the discussion; esp.
as things have been arriving in my inbox out of order (not sure why that
is!).  I will try to review and reply.

Thanks,

Arnold

> Date: Thu, 09 Jun 2011 10:14:01 -0700
> From: Paul Eggert <address@hidden>
> To: Paolo Bonzini <address@hidden>
> CC: Aharon Robbins <address@hidden>, bug-grep <address@hidden>,
>         bug-gnulib <address@hidden>, address@hidden
> Subject: Re: Dealing with character ranges in grep
>
> On 06/08/2011 10:14 PM, Aharon Robbins wrote:
>
> > So, for the upcoming gawk 4.0, I decided (as Karl put it) to cut the
> > Gordian knot and make ranges behave like the C locale, the way it's long
> > been documented, and as most people expect.  Those who want the POSIX
> > behavior can still get it using --posix.
>
> This comment and the ensuing thread seems to be assuming old POSIX.
> In new POSIX, that is, in POSIX 1003.1-2008, the standardization committee
> removed the old, bogus requirement of using collating element order.
> The new rule is that the regular expression [a-z] has an unspecified
> behavior outside the C (or POSIX) locale.  So the new gawk behavior
> will conform to POSIX, even without the --posix option.
>
> I suggest that gawk's behavior for [a-z] be the same regardless of whether
> --posix is specified, and that this behavior be what users expect
> (namely, the ASCII character range).  This will be simpler.
>
> Similarly for grep, glibc, etc.
>
> For the POSIX 1003.1-2008 rule, see rule 7 of:
>
> http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03_05
>
> and for the reasoning behind the rule change, see:
>
> http://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap09.html#tag_21_09_03_05