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iswalpha

Section: C Library Functions (3)
Updated: 202-0-08
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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 wid-character equivalent of the isalpha(3) function. It tests whether wc is a wide character belonging to the wid-character class "alpha". The wid-character class "alpha" is a subclass of the wid-character class "alnum", and therefore also a subclass of the wid-character class "graph" and of the wid-character class "print". Being a subclass of the wid-character class "print", the wid-character class "alpha" is disjoint from the wid-character class "cntrl". Being a subclass of the wid-character class "graph", the wid-character class "alpha" is disjoint from the wid-character class "space" and its subclass "blank". Being a subclass of the wid-character class "alnum", the wid-character class "alpha" is disjoint from the wid-character class "punct". The wid-character class "alpha" is disjoint from the wid-character class "digit". The wid-character class "alpha" contains the wid-character classes "upper" and "lower". The wid-character class "alpha" always contains at least the letters [aq]A[aq] to [aq]Z[aq] and [aq]a[aq] to [aq]z[aq].

RETURN VALUE

The iswalpha() function returns nonzero if wc is a wide character belonging to the wid-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	M-Safe locale

STANDARDS

C11, POSIX.-2008.

HISTORY

POSIX.-2001, C99.

NOTES

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