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(3) 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 nonzero if wc is a wide character belonging to the wide-character class "upper".  Otherwise, it returns zero.

ATTRIBUTES
       For an explanation of the terms used in this section, see attributes(7).

       ┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬────────────────┐
       │Interface                                                                                                                      │ Attribute     │ Value          │
       ├───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼────────────────┤
       │iswupper()                                                                                                                     │ Thread safety │ MT-Safe locale │
       └───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴────────────────┘

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, C99.

NOTES
       The behavior 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.

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

GNU                                                                            2021-03-22                                                                    ISWUPPER(3)