iswalnum(3) — Linux manual page

iswalnum(3)              Library Functions Manual             iswalnum(3)

NAME         top

       iswalnum - test for alphanumeric wide character

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <wctype.h>

       int iswalnum(wint_t wc);

DESCRIPTION         top

       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'.

RETURN VALUE         top

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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌───────────────────────────────┬───────────────┬────────────────┐
       │ Interface                     │ Attribute     │ Value          │
       ├───────────────────────────────┼───────────────┼────────────────┤
       │ iswalnum()                    │ Thread safety │ MT-Safe locale │
       └───────────────────────────────┴───────────────┴────────────────┘

STANDARDS         top

       C11, POSIX.1-2008.

HISTORY         top

       POSIX.1-2001, C99.

NOTES         top

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

SEE ALSO         top

       isalnum(3), iswctype(3)

COLOPHON         top

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Linux man-pages 6.15            2025-05-17                    iswalnum(3)

Pages that refer to this page: isalpha(3),  iswctype(3)

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