ISWCTYPE(3) Library Functions Manual ISWCTYPE(3)

iswctype
test a character for character class identifier

Standard C Library (libc, -lc)

#include <wctype.h>

int
iswctype(wint_t wc, wctype_t charclass);

The iswctype() function returns a boolean value that indicates whether a wide character wc is in charclass.

The behaviour of iswctype() is undefined if the iswctype() function is called with an invalid charclass (changes of LC_CTYPE category invalidate charclass) or invalid wide character wc.

The behaviour of iswctype() is affected by the LC_CTYPE category of the current locale.

The iswctype() returns:
0
wc is not in charclass.
non-zero
wc is in charclass.

No errors are defined.

setlocale(3), towctrans(3), wctrans(3), wctype(3)

The iswctype() function conforms to ISO/IEC 9899/AMD1:1995 (“ISO C90, Amendment 1”).
March 4, 2003 NetBSD 9.0