xref: /titanic_41/usr/src/man/man3c/mbrtowc.3c (revision 8b1606b5d15e5e037182f32e0306c43206772082)
te
Copyright (c) 1992, X/Open Company Limited. All Rights Reserved. Portions Copyright (c) 2003, Sun Microsystems, Inc. All Rights Reserved.
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 Sun OS 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]
MBRTOWC 3C "Nov 1, 2003"
NAME
mbrtowc - convert a character to a wide-character code (restartable)
SYNOPSIS

#include <wchar.h>

size_t mbrtowc(wchar_t *restrict pwc, const char *restrict s, size_t n,
 mbstate_t *restrict ps);
DESCRIPTION

If s is a null pointer, the mbrtowc() function is equivalent to the call:

mbrtowc(NULL, ``'', 1, ps)

In this case, the values of the arguments pwc and n are ignored.

If s is not a null pointer, the mbrtowc() function inspects at most n bytes beginning at the byte pointed to by s to determine the number of bytes needed to complete the next character (including any shift sequences). If the function determines that the next character is completed, it determines the value of the corresponding wide-character and then, if pwc is not a null pointer, stores that value in the object pointed to by pwc. If the corresponding wide-character is the null wide-character, the resulting state described is the initial conversion state.

If ps is a null pointer, the mbrtowc() function uses its own internal mbstate_t object, which is initialized at program startup to the initial conversion state. Otherwise, the mbstate_t object pointed to by ps is used to completely describe the current conversion state of the associated character sequence. Solaris will behave as if no function defined in the Solaris Reference Manual calls mbrtowc().

The behavior of this function is affected by the LC_CTYPE category of the current locale. See environ(5).

RETURN VALUES

The mbrtowc() function returns the first of the following that applies: 0

If the next n or fewer bytes complete the character that corresponds to the null wide-character (which is the value stored).

positive

If the next n or fewer bytes complete a valid character (which is the value stored); the value returned is the number of bytes that complete the character.

(size_t)-2

If the next n bytes contribute to an incomplete but potentially valid character, and all n bytes have been processed (no value is stored). When n has at least the value of the MB_CUR_MAX macro, this case can only occur if s points at a sequence of redundant shift sequences (for implementations with state-dependent encodings).

(size_t)-1

If an encoding error occurs, in which case the next n or fewer bytes do not contribute to a complete and valid character (no value is stored). In this case, EILSEQ is stored in errno and the conversion state is undefined.

ERRORS

The mbrtowc() function may fail if: EINVAL

The ps argument points to an object that contains an invalid conversion state.

EILSEQ

Invalid character sequence is detected.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Standard
MT-Level See NOTES below
SEE ALSO

mbsinit(3C), setlocale(3C), attributes(5), environ(5), standards(5)

NOTES

If ps is not a null pointer, mbrtowc() uses the mbstate_t object pointed to by ps and the function can be used safely in multithreaded applications, as long as setlocale(3C) is not being called to change the locale. If ps is a null pointer, mbrtowc() uses its internal mbstate_t object and the function is Unsafe in multithreaded applications.