Originální popis anglicky:
iswalpha - test for alphabetic wide character
Návod, kniha: Linux Programmer's Manual
#include <wctype.h>
int iswalpha(wint_t wc);
The
iswalpha function is the wide-character equivalent of the
isalpha function. It tests whether
wc is a wide character
belonging to the wide character class "alpha".
The wide character class "alpha" is a subclass of the wide character
class "alnum", and therefore also a subclass 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 "alpha" is disjoint from the wide character class
"cntrl".
Being a subclass of the wide character class "graph", the wide
character class "alpha" 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 "alpha" is disjoint from the wide character class
"punct".
The wide character class "alpha" is disjoint from the wide character
class "digit".
The wide character class "alpha" contains the wide character classes
"upper" and "lower".
The wide character class "alpha" always contains at least the letters
'A' to 'Z' and 'a' to 'z'.
The
iswalpha function returns non-zero if
wc is a wide character
belonging to the wide character class "alpha". Otherwise it returns
zero.
ISO/ANSI C, UNIX98
isalpha(3),
iswctype(3)
The behaviour of
iswalpha depends on the LC_CTYPE category of the current
locale.
