iswupper - Man Page

Standard C library (libc, -lc)

#include <wctype.h>

int iswupper(wint_t wc);

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'.

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

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

C11, POSIX.1-2008.

POSIX.1-2001, C99.

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.

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

isalpha(3), iswctype(3), towupper(3).