redhat man page for iswupper

ISWUPPER(3)						     Linux Programmer's Manual						       ISWUPPER(3)

NAME
       iswupper - test for uppercase wide character

SYNOPSIS
       #include <wctype.h>

       int iswupper(wint_t wc);

DESCRIPTION
       The  iswupper  function	is the wide-character equivalent of the isupper function. It tests whether wc is a wide character belonging to the
       wide character class "upper".

       The wide character class "upper" is a subclass of the wide character class "alpha", and therefore also a subclass  of  the  wide  character
       class "alnum", of the wide character class "graph" and of the wide character class "print".

       Being a subclass of the wide character class "print", the wide character class "upper" is disjoint from the wide character class "cntrl".

       Being  a  subclass  of the wide character class "graph", the wide character class "upper" is disjoint from the wide character class "space"
       and its subclass "blank".

       Being a subclass of the wide character class "alnum", the wide character class "upper" is disjoint from the wide character class "punct".

       Being a subclass of the wide character class "alpha", the wide character class "upper" is disjoint from the wide character class "digit".

       The wide character class "upper" contains at least those characters wc which are equal to towupper(wc) and different from towlower(wc).

       The wide character class "upper" always contains at least the letters 'A' to 'Z'.

RETURN VALUE
       The iswupper function returns non-zero if wc is a wide character belonging to the wide character class "upper". Otherwise it returns zero.

CONFORMING TO
       ISO/ANSI C, UNIX98

SEE ALSO
       isupper(3), iswctype(3), towupper(3)

NOTES
       The behaviour of iswupper depends on the LC_CTYPE category of the current locale.

       This function is not very appropriate for dealing with Unicode characters, because Unicode knows about three cases: upper, lower and  title
       case.

GNU
								    1999-07-25							       ISWUPPER(3)