ISWXDIGIT(3) Linux Programmer's Manual ISWXDIGIT(3)

iswxdigit - test for hexadecimal digit wide character

#include <wctype.h>
int iswxdigit(wint_t wc);

The iswxdigit() function is the wide-character equivalent of the isxdigit(3) function. It tests whether wc is a wide character belonging to the wide-character class "xdigit".
The wide-character class "xdigit" 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 "xdigit" is disjoint from the wide-character class "cntrl".
Being a subclass of the wide-character class "graph", the wide-character class "xdigit" 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 "xdigit" is disjoint from the wide-character class "punct".
The wide-character class "xdigit" always contains at least the letters 'A' to 'F', 'a' to 'f' and the digits '0' to '9'.

The iswxdigit() function returns nonzero if wc is a wide character belonging to the wide-character class "xdigit". Otherwise, it returns zero.

For an explanation of the terms used in this section, see attributes(7).
Interface Attribute Value
iswxdigit () Thread safety MT-Safe locale

POSIX.1-2001, POSIX.1-2008, C99.

The behavior of iswxdigit() depends on the LC_CTYPE category of the current locale.

iswctype(3), isxdigit(3)
2015-08-08 GNU