iswalpha(3)		    Library Functions Manual		     iswalpha(3)

NAME
     iswalpha - test for alphabetic wide character

LIBRARY
     Standard C library (libc, -lc)

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  "up-
     per" 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).
     allbox; lbx lb lb l l l.  Interface Attribute Value T{ iswalpha()
     T}	  Thread safety	  MT-Safe locale

STANDARDS
     C11, POSIX.1-2008.

HISTORY
     POSIX.1-2001, C99.

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

SEE ALSO
     isalpha(3), iswctype(3)

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