table of contents
iswupper(3) | Library Functions Manual | iswupper(3) |
NAME¶
iswupper - test for uppercase wide character
LIBRARY¶
Standard C library (libc, -lc)
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 |
STANDARDS¶
C11, POSIX.1-2008.
HISTORY¶
POSIX.1-2001, 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¶
2024-05-02 | Linux man-pages 6.9.1 |