Re: Locale aware range expressions?

[Paul Eggert]

On 2024-01-28 07:17, arnold@skeeve.com wrote:
> I think this is a bug in the documentation; the regex and dfa
> libraries these days use Rational Range Interpretation(tm).
>
> Paul, do you agree?

It depends on how 'grep' was built. If it was configured via 
'./configure --with-included-regex', we get Rational Range 
Interpretation (RRI) behavior:

  $ printf '%s\n' d ḑ D Ḑ e E é É f ḟ F Ḟ | src/grep '[d-f]'
  d
  e
  f

However, I just checked, and both Fedora and Ubuntu grep use glibc's 
regex code which does not use RRI, so the behavior when 
LC_ALL='en_US.utf8' is:

  $ printf '%s\n' d ḑ D Ḑ e E é É f ḟ F Ḟ | grep '[d-f]'
  d
  ḑ
  e
  é
  f

One way to fix this would be to change glibc - what's been happening in 
that area?