On 12/04/2010 02:49 PM, Lee Rothstein wrote: > Therefore, instead of using '[A-Z]' to represent caps, I should > have used (?) the Posixly Correct, '[:upper:]'.
POSIX 2001 and 2008 says that [A-Z] when used as a glob or as a regex is defined _only_ in the C locale; in all other locales, it's behavior is unspecified. Meanwhile, [[:upper:]] (note the double [ and ]) is well-defined in all locales (the next version of POSIX will make it more obvious that [:upper:] might be treated as either [:epru] or [[:upper:]], if not outright rejected as an error). It all stems from the earlier POSIX 1992, which required [A-Z] to match collation order in all locales. POSIX 2001 withdrew that requirement based on how many people it confused, but the damage was already done - it is no longer portable because of people that literally implemented the older requirement (bash included). Now, what would be really nice is if all implementations treated unspecified behavior for [A-Z] as meaning a sane synonym for [[:upper:]], but that's not going to happen any time soon. -- Eric Blake ebl...@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
