1.\" Copyright (c) 2002-2004 Tim J. Robbins. All rights reserved. 2.\" Copyright (c) 1993 3.\" The Regents of the University of California. All rights reserved. 4.\" 5.\" This code is derived from software contributed to Berkeley by 6.\" Donn Seeley of BSDI. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" From @(#)multibyte.3 8.1 (Berkeley) 6/4/93 37.\" From FreeBSD: src/lib/libc/locale/multibyte.3,v 1.22 2003/11/08 03:23:11 tjr Exp 38.\" $FreeBSD$ 39.\" 40.Dd April 11, 2004 41.Dt MBTOWC 3 42.Os 43.Sh NAME 44.Nm mbtowc 45.Nd convert a character to a wide-character code 46.Sh LIBRARY 47.Lb libc 48.Sh SYNOPSIS 49.In stdlib.h 50.Ft int 51.Fn mbtowc "wchar_t * restrict wcharp" "const char * restrict mbchar" "size_t nbytes" 52.Sh DESCRIPTION 53The 54.Fn mbtowc 55function converts a multibyte character 56.Fa mbchar 57into a wide character according to the current conversion state, 58and stores the result 59in the object pointed to by 60.Fa wcharp . 61Up to 62.Fa nbytes 63bytes are examined. 64.Pp 65A call with a null 66.Fa mbchar 67pointer returns nonzero if the current encoding requires shift states, 68zero otherwise; 69if shift states are required, the shift state is reset to the initial state. 70.Sh RETURN VALUES 71If 72.Fa mbchar 73is 74.Dv NULL , 75the 76.Fn mbtowc 77function returns nonzero if shift states are supported, 78zero otherwise. 79.Pp 80Otherwise, if 81.Fa mbchar 82is not a null pointer, 83.Fn mbtowc 84either returns 0 if 85.Fa mbchar 86represents the null wide character, or returns 87the number of bytes processed in 88.Fa mbchar , 89or returns \-1 if no multibyte character 90could be recognized or converted. 91In this case, 92.Fn mbtowc Ns No 's 93internal conversion state is undefined. 94.Sh ERRORS 95The 96.Fn mbtowc 97function will fail if: 98.Bl -tag -width Er 99.It Bq Er EILSEQ 100An invalid multibyte sequence was detected. 101.It Bq Er EINVAL 102The internal conversion state is invalid. 103.El 104.Sh SEE ALSO 105.Xr btowc 3 , 106.Xr mblen 3 , 107.Xr mbrtowc 3 , 108.Xr mbstowcs 3 , 109.Xr multibyte 3 , 110.Xr wctomb 3 111.Sh STANDARDS 112The 113.Fn mbtowc 114function conforms to 115.St -isoC-99 . 116