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