ISWUPPER(3) Linux Programmer's Manual ISWUPPER(3)
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 isup-
per(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-charac-
ter class "upper" is disjoint from the wide-character class "cntrl".
Being a subclass of the wide-character class "graph", the wide-charac-
ter 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-charac-
ter class "upper" is disjoint from the wide-character class "punct".
Being a subclass of the wide-character class "alpha", the wide-charac-
ter 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 be-
longing to the wide-character class "upper". Otherwise, it returns
zero.
ATTRIBUTES
For an explanation of the terms used in this section, see at-
tributes(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 cur-
rent locale.
This function is not very appropriate for dealing with Unicode charac-
ters, because Unicode knows about three cases: upper, lower and title
case.
SEE ALSO
isupper(3), iswctype(3), towupper(3)
COLOPHON
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GNU 2015-08-08 ISWUPPER(3)