> Where have you found this?
>
> I've been looking for that but have not found it. I run a rh9 system, do
> you have something newer? Maybe I have just not looked in the right place
> in the documentation.
Glibc 2.3 implements both reentrant and a thread local locale APIs.
The reentrant API provides versions of isalpha, isupper, toupper,
strcoll, and so on that take a separate locale parameter.
The thread locale API is simpler - it adds new a uselocale() function,
that once called places a thread in its own thread specific local,
after which all locale dependent functions use the thread locale
instead of the global one (which is the default for backward
compatibility).
See this paper for details:
http://people.redhat.com/drepper/lt2002talk.pdf