iswupper - test for uppercase wide character
#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).
| Interface | Attribute | Value |
| iswupper() | Thread safety | MT-Safe locale |
POSIX.1-2001, POSIX.1-2008, 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)
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