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.Fo mbtowc 52.Fa "wchar_t * restrict wcharp" "const char * restrict mbchar" 53.Fa "size_t nbytes" 54.Fc 55.Sh DESCRIPTION 56The 57.Fn mbtowc 58function converts a multibyte character 59.Fa mbchar 60into a wide character according to the current conversion state, 61and stores the result 62in the object pointed to by 63.Fa wcharp . 64Up to 65.Fa nbytes 66bytes are examined. 67.Pp 68A call with a null 69.Fa mbchar 70pointer returns nonzero if the current encoding requires shift states, 71zero otherwise; 72if shift states are required, the shift state is reset to the initial state. 73.Sh RETURN VALUES 74If 75.Fa mbchar 76is 77.Dv NULL , 78the 79.Fn mbtowc 80function returns nonzero if shift states are supported, 81zero otherwise. 82.Pp 83Otherwise, if 84.Fa mbchar 85is not a null pointer, 86.Fn mbtowc 87either returns 0 if 88.Fa mbchar 89represents the null wide character, or returns 90the number of bytes processed in 91.Fa mbchar , 92or returns \-1 if no multibyte character 93could be recognized or converted. 94In this case, 95.Fn mbtowc Ns 's 96internal conversion state is undefined. 97.Sh ERRORS 98The 99.Fn mbtowc 100function will fail if: 101.Bl -tag -width Er 102.It Bq Er EILSEQ 103An invalid multibyte sequence was detected. 104.It Bq Er EINVAL 105The internal conversion state is invalid. 106.El 107.Sh SEE ALSO 108.Xr btowc 3 , 109.Xr mblen 3 , 110.Xr mbrtowc 3 , 111.Xr mbstowcs 3 , 112.Xr multibyte 3 , 113.Xr wctomb 3 114.Sh STANDARDS 115The 116.Fn mbtowc 117function conforms to 118.St -isoC-99 . 119