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