ISWDIGIT(3) Linux Programmer's Manual ISWDIGIT(3) NAME iswdigit - test for decimal digit wide character SYNOPSIS #include <wctype.h> int iswdigit(wint_t wc); DESCRIPTION The iswdigit() function is the wide-character equivalent of the isdigit(3) function. It tests whether wc is a wide character belonging to the wide-character class "digit". The wide-character class "digit" is a subclass of the wide-character class "xdigit", and therefore also a subclass of the wide-character class "alnum", 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 "digit" is disjoint from the wide-character class "cntrl". Being a subclass of the wide-character class "graph", the wide-character class "digit" 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 "digit" is disjoint from the wide-character class "punct". The wide-character class "digit" is disjoint from the wide-character class "alpha" and therefore also disjoint from its subclasses "lower", "upper". The wide-character class "digit" always contains exactly the digits '0' to '9'. RETURN VALUE The iswdigit() function returns nonzero if wc is a wide character belonging to the wide-character class "digit". Otherwise, it returns zero. ATTRIBUTES For an explanation of the terms used in this section, see attributes(7). ┌───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬────────────────┐ │Interface │ Attribute │ Value │ ├───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼────────────────┤ │iswdigit() │ Thread safety │ MT-Safe locale │ └───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴────────────────┘ CONFORMING TO POSIX.1-2001, POSIX.1-2008, C99. NOTES The behavior of iswdigit() depends on the LC_CTYPE category of the current locale. SEE ALSO isdigit(3), iswctype(3) GNU 2021-03-22 ISWDIGIT(3)