iswalnum(3) Library Functions Manual iswalnum(3)

iswalnum - test for alphanumeric wide character

Standard C library (libc, -lc)

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

The iswalnum() function is the wide-character equivalent of the isalnum(3) function. It tests whether wc is a wide character belonging to the wide-character class "alnum".

The wide-character class "alnum" is a subclass of the wide-character class "graph", and therefore also a subclass of the wide-character class "print".

Being a subclass of the wide-character class "print", the wide-character class "alnum" is disjoint from the wide-character class "cntrl".

Being a subclass of the wide-character class "graph", the wide-character class "alnum" is disjoint from the wide-character class "space" and its subclass "blank".

The wide-character class "alnum" is disjoint from the wide-character class "punct".

The wide-character class "alnum" is the union of the wide-character classes "alpha" and "digit". As such, it also contains the wide-character class "xdigit".

The wide-character class "alnum" always contains at least the letters 'A' to 'Z', 'a' to 'z', and the digits '0' to '9'.

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

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
iswalnum () Thread safety MT-Safe locale

C11, POSIX.1-2008.

POSIX.1-2001, C99.

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

isalnum(3), iswctype(3)

2023-10-31 Linux man-pages 6.7