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.\" 32.\" From @(#)multibyte.3 8.1 (Berkeley) 6/4/93 33.\" From FreeBSD: src/lib/libc/locale/multibyte.3,v 1.22 2003/11/08 03:23:11 tjr Exp 34.\" 35.Dd April 11, 2004 36.Dt MBTOWC 3 37.Os 38.Sh NAME 39.Nm mbtowc 40.Nd convert a character to a wide-character code 41.Sh LIBRARY 42.Lb libc 43.Sh SYNOPSIS 44.In stdlib.h 45.Ft int 46.Fo mbtowc 47.Fa "wchar_t * restrict wcharp" "const char * restrict mbchar" 48.Fa "size_t nbytes" 49.Fc 50.Sh DESCRIPTION 51The 52.Fn mbtowc 53function converts a multibyte character 54.Fa mbchar 55into a wide character according to the current conversion state, 56and stores the result 57in the object pointed to by 58.Fa wcharp . 59Up to 60.Fa nbytes 61bytes are examined. 62.Pp 63A call with a null 64.Fa mbchar 65pointer returns nonzero if the current encoding requires shift states, 66zero otherwise; 67if shift states are required, the shift state is reset to the initial state. 68.Sh RETURN VALUES 69If 70.Fa mbchar 71is 72.Dv NULL , 73the 74.Fn mbtowc 75function returns nonzero if shift states are supported, 76zero otherwise. 77.Pp 78Otherwise, if 79.Fa mbchar 80is not a null pointer, 81.Fn mbtowc 82either returns 0 if 83.Fa mbchar 84represents the null wide character, or returns 85the number of bytes processed in 86.Fa mbchar , 87or returns \-1 if no multibyte character 88could be recognized or converted. 89In this case, 90.Fn mbtowc Ns 's 91internal conversion state is undefined. 92.Sh ERRORS 93The 94.Fn mbtowc 95function will fail if: 96.Bl -tag -width Er 97.It Bq Er EILSEQ 98An invalid multibyte sequence was detected. 99.It Bq Er EINVAL 100The internal conversion state is invalid. 101.El 102.Sh SEE ALSO 103.Xr btowc 3 , 104.Xr mblen 3 , 105.Xr mbrtowc 3 , 106.Xr mbstowcs 3 , 107.Xr multibyte 3 , 108.Xr wctomb 3 109.Sh STANDARDS 110The 111.Fn mbtowc 112function conforms to 113.St -isoC-99 . 114