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.\" 4. 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.\" $FreeBSD: head/lib/libc/locale/mbtowc.3 165903 2007-01-09 00:28:16Z imp $ 35.\" 36.Dd April 11, 2004 37.Dt MBTOWC 3 38.Os 39.Sh NAME 40.Nm mbtowc 41.Nd convert a character to a wide-character code 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In stdlib.h 46.Ft int 47.Fo mbtowc 48.Fa "wchar_t * restrict wcharp" "const char * restrict mbchar" 49.Fa "size_t nbytes" 50.Fc 51.Sh DESCRIPTION 52The 53.Fn mbtowc 54function converts a multibyte character 55.Fa mbchar 56into a wide character according to the current conversion state, 57and stores the result 58in the object pointed to by 59.Fa wcharp . 60Up to 61.Fa nbytes 62bytes are examined. 63.Pp 64A call with a null 65.Fa mbchar 66pointer returns nonzero if the current encoding requires shift states, 67zero otherwise; 68if shift states are required, the shift state is reset to the initial state. 69.Sh RETURN VALUES 70If 71.Fa mbchar 72is 73.Dv NULL , 74the 75.Fn mbtowc 76function returns nonzero if shift states are supported, 77zero otherwise. 78.Pp 79Otherwise, if 80.Fa mbchar 81is not a null pointer, 82.Fn mbtowc 83either returns 0 if 84.Fa mbchar 85represents the null wide character, or returns 86the number of bytes processed in 87.Fa mbchar , 88or returns \-1 if no multibyte character 89could be recognized or converted. 90In this case, 91.Fn mbtowc Ns 's 92internal conversion state is undefined. 93.Sh ERRORS 94The 95.Fn mbtowc 96function will fail if: 97.Bl -tag -width Er 98.It Bq Er EILSEQ 99An invalid multibyte sequence was detected. 100.It Bq Er EINVAL 101The internal conversion state is invalid. 102.El 103.Sh SEE ALSO 104.Xr btowc 3 , 105.Xr mblen 3 , 106.Xr mbrtowc 3 , 107.Xr mbstowcs 3 , 108.Xr multibyte 3 , 109.Xr wctomb 3 110.Sh STANDARDS 111The 112.Fn mbtowc 113function conforms to 114.St -isoC-99 . 115