Sun Microsystems, Inc. gratefully acknowledges The Open Group for
permission to reproduce portions of its copyrighted documentation.
Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.

The Institute of Electrical and Electronics Engineers and The Open
Group, have given us permission to reprint portions of their
documentation.

In the following statement, the phrase ``this text'' refers to portions
of the system documentation.

Portions of this text are reprinted and reproduced in electronic form
in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6,
Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy
between these versions and the original IEEE and The Open Group
Standard, the original IEEE and The Open Group Standard is the referee
document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html.

This notice shall appear on any product containing this material.

The contents of this file are subject to the terms of the
Common Development and Distribution License (the "License").
You may not use this file except in compliance with the License.

You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
or http://www.opensolaris.org/os/licensing.
See the License for the specific language governing permissions
and limitations under the License.

When distributing Covered Code, include this CDDL HEADER in each
file and include the License file at usr/src/OPENSOLARIS.LICENSE.
If applicable, add the following below this CDDL HEADER, with the
fields enclosed by brackets "[]" replaced with your own identifying
information: Portions Copyright [yyyy] [name of copyright owner]


Copyright 1989 AT&T
Copyright (c) 1992, X/Open Company Limited. All Rights Reserved.
Portions Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved
Copyright 2014 Garrett D'Amore <garrett@damore.org>

mblen, mblen_l - get number of bytes in a character

#include <stdlib.h>

int mblen(const char *s, size_t n);

#include <stdlib.h>
#include <xlocale.h>

int mblen_l(const char *s, size_t n, locale_t loc);

If s is not a null pointer, mblen() and mblen_l() determine the number of bytes constituting the character pointed to by s. The call

mblen(s, n);

is equivalent to:

mbtowc((wchar_t *)0, s, n);

A call with s as a null pointer causes this function to return 0.

Whereas the behavior of the mblen() function is affected by the LC_CTYPE category of the current locale, the behavior of mblen_l() is affected by the LC_CTYPE category of the locale specified by loc.

If s is a null pointer, mblen() and mblen_l() returns 0. It s is not a null pointer, mblen() and mblen_l() returns 0 (if s points to the null byte), the number of bytes that constitute the character (if the next n or fewer bytes form a valid character), or -1 (if they do not form a valid character) and may set errno to indicate the error. In no case will the value returned be greater than n or the value of the MB_CUR_MAX macro.

The mblen() and mblen_l() functions may fail if: EILSEQ

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE

CSI Enabled

Interface Stability See below.

MT-Level MT-Safe

The mblen() function is Standard. The mblen_l() function is Uncommitted.

mbstowcs(3C), mbtowc(3C), newlocale(3C), setlocale(3C), wcstombs(3C), wctomb(3C), uselocale(3C) attributes(7), standards (7)