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iswalpha(3) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | STANDARDS | HISTORY | NOTES | SEE ALSO | COLOPHON 

iswalpha(3)              Library Functions Manual             iswalpha(3)

NAME         top

       iswalpha - test for alphabetic wide character

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <wctype.h>

       int iswalpha(wint_t wc);

DESCRIPTION         top

       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         top

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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       โ”Œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”
       โ”‚ Interface                     โ”‚ Attribute     โ”‚ Value          โ”‚
       โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ค
       โ”‚ iswalpha()                    โ”‚ Thread safety โ”‚ MT-Safe locale โ”‚
       โ””โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”˜

STANDARDS         top

       C11, POSIX.1-2008.

HISTORY         top

       POSIX.1-2001, C99.

NOTES         top

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

SEE ALSO         top

       isalpha(3), iswctype(3)

COLOPHON         top

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Linux man-pages 6.18            2026-02-08                    iswalpha(3)

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