Manpages - iswupper.3
Table of Contents
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)
COLOPHON
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