- define character class
#include <wchar.h> wctype_t wctype(const char *charclass);
The wctype() function is defined for valid character class names as defined in the current locale. The charclass is a string identifying a generic character class for which codeset-specific type information is required. The following character class names are defined in all locales:
Additional character class names defined in the locale definition file (category LC_CTYPE) can also be specified.
The function returns a value of type wctype_t, which can be used as the second argument to subsequent calls of iswctype(3C). wctype() determines values of wctype_t according to the rules of the coded character set defined by character type information in the program's locale (category LC_CTYPE). The values returned by wctype() are valid until a call to setlocale(3C) that modifies the category LC_CTYPE.
The wctype() function returns 0 if the given character class name is not valid for the current locale (category LC_CTYPE); otherwise it returns an object of type wctype_t that can be used in calls to iswctype().
See attributes(5) for descriptions of the following attributes: