iswupper(3) — Linux manual page

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

NAME         top

       iswupper - test for uppercase wide character

SYNOPSIS         top

       #include <wctype.h>

       int iswupper(wint_t wc);

DESCRIPTION         top

       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         top

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

ATTRIBUTES         top

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

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

CONFORMING TO         top

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

NOTES         top

       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         top

       isupper(3), iswctype(3), towupper(3)

COLOPHON         top

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       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at
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GNU                            2021-03-22                    ISWUPPER(3)

Pages that refer to this page: isalpha(3),  iswctype(3),  towupper(3)

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