| ISWUPPER(3) | Linux Programmer's Manual | ISWUPPER(3) |
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 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 non-zero if wc is a wide character belonging to the wide character class "upper". Otherwise it returns zero.
ISO/ANSI C, UNIX98
The behaviour 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.
| July 25, 1999 | GNU |