.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
.\"
.\" This is free documentation; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation; either version 2 of
.\" the License, or (at your option) any later version.
.\"
.\" 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
.\"
.TH WCSNLEN 3  2011-10-01 "GNU" "Linux Programmer's Manual"
.SH NAME
wcsnlen \- determine the length of a fixed-size wide-character string
.SH SYNOPSIS
.nf
.B #include <wchar.h>
.sp
.BI "size_t wcsnlen(const wchar_t *" s ", size_t " maxlen );
.fi
.sp
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.sp
.BR wcsnlen ():
.PD 0
.ad l
.RS 4
.TP 4
Since glibc 2.10:
_XOPEN_SOURCE\ >=\ 700 || _POSIX_C_SOURCE\ >=\ 200809L
.TP
Before glibc 2.10:
_GNU_SOURCE
.RE
.ad
.PD
.SH DESCRIPTION
The
.BR wcsnlen ()
function is the wide-character equivalent
of the
.BR strnlen (3)
function.
It returns the number of wide-characters in the string pointed to by
\fIs\fP, not including the terminating null wide character (L\(aq\\0\(aq),
but at most
\fImaxlen\fP
wide characters (note: this parameter is not a byte count).
In doing this,
.BR wcsnlen ()
looks only at the first \fImaxlen\fP
wide characters at \fIs\fP and never beyond \fIs+maxlen\fP.
.SH "RETURN VALUE"
The
.BR wcsnlen ()
function returns \fIwcslen(s)\fP, if that is less than
\fImaxlen\fP, or \fImaxlen\fP if there is no null wide character among the
first \fImaxlen\fP wide characters pointed to by \fIs\fP.
.SH VERSIONS
The
.BR wcsnlen ()
function is provided in glibc since version 2.1.
.SH "CONFORMING TO"
POSIX.1-2008.
.SH "SEE ALSO"
.BR strnlen (3),
.BR wcslen (3)
.SH COLOPHON
This page is part of release 3.44 of the Linux
.I man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.