Re: [bug-gawk] Does gawk character classes follow this?

[arnold]

Hi Eli.

Eli Zaretskii <address@hidden> wrote:

> > [:alnum:]   [a-zA-Z0-9]
> > [:alpha:]   [a-zA-Z]
> > [:ascii:]   [\x00-\x7F]
> > [:cntrl:]  [\x00-\x1F\x7F]
>
> Doesn't the meaning of these character classes depend on the
> implementation of the regex library with which Gawk was linked?

Yes and no. Gawk always links with the included regex and dfa routines,
so there really isn't an option to use a different regex library.

That said, gawk's routines use the underlying C library ctype/wctype
routines to check those classes. (Gawk doesn't have [:ascii:], by
the way.)

On systems that understand locales, the C library returns true/false
for a given character / wide character based on the locale's settings.

HTH,

Arnold