.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
.\"
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.\" References consulted:
.\"   GNU glibc-2 source code and manual
.\"   Dinkumware C library reference http://www.dinkumware.com/
.\"   OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html
.\"   ISO/IEC 9899:1999
.\"
.TH ISWBLANK 3  2014-02-10 "GNU" "Linux Programmer's Manual"
.SH NAME
iswblank \- test for whitespace wide character
.SH SYNOPSIS
.nf
.B #include <wctype.h>
.sp
.BI "int iswblank(wint_t " wc );
.fi
.sp
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.sp
.ad l
.BR iswblank ():
.RS
_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE\ >=\ 200112L;
.br
or
.I cc\ -std=c99
.RE
.ad
.SH DESCRIPTION
The
.BR iswblank ()
function is the wide-character equivalent of the
.BR isblank (3)
function.
It tests whether \fIwc\fP is a wide character
belonging to the wide-character class "blank".
.PP
The wide-character class "blank" is a subclass of the wide-character class
"space".
.PP
Being a subclass of the wide-character class "space",
the wide-character class "blank" is disjoint from the
wide-character class "graph" and therefore also disjoint
from its subclasses "alnum", "alpha", "upper", "lower", "digit",
"xdigit", "punct".
.PP
The wide-character class "blank" always contains
at least the space character
and the control character \(aq\\t\(aq.
.SH RETURN VALUE
The
.BR iswblank ()
function returns nonzero
if \fIwc\fP is a wide character
belonging to the wide-character class "blank".
Otherwise, it returns zero.
.SH ATTRIBUTES
.SS Multithreading (see pthreads(7))
The
.BR iswblank ()
function is thread-safe with exceptions.
It can be safely used in multithreaded applications, as long as
.BR setlocale (3)
is not called to change the locale during its execution.
.SH CONFORMING TO
POSIX.1-2001.
.SH NOTES
The behavior of
.BR iswblank ()
depends on the
.B LC_CTYPE
category of the
current locale.
.SH SEE ALSO
.BR isblank (3),
.BR iswctype (3)
.SH COLOPHON
This page is part of release 3.74 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%http://www.kernel.org/doc/man\-pages/.