On 09/06/2018 09:17 AM, Chet Ramey wrote:
On 9/5/18 4:39 PM, Eric Blake wrote:
Or, you can use bash's 'shopt -s globasciiranges' which is
supposed to enable Rational Range Interpretation, where even in non-C
locales, a character range bounded by two ASCII characters takes on the C
locale definition of only the ASCII characters in that range, rather than
the locale's definition of whatever other characters might also be
equivalent (actually, while I know that shopt affects globbing, I don't
know if it also affects regex matching - but if it doesn't, that's probably
a bug that should be fixed).
Since bash uses the C library's regexp engine, and most C libraries don't
implement RRI, much less expose it as a flags option available via
regcomp(), there's no reason to expect that globasciiranges would have
any effect on regular expression matching.
But bash could be taught to convert any regex that contains a range with
both endpoints ASCII into a different bracket expression before handing
things over to regcomp(). That is, if the user is matching against
[a-d], bash hands [abcd] to regcomp() instead. You don't need a flag in
regcomp() to get RRI, just merely some pre-processing (and often memory
allocation, as the expansion of a range into a non-range tends to
require more characters).
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
