.\" Copyright (c) 2002 Tim J. Robbins .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $FreeBSD: src/lib/libc/locale/mbrtowc.3,v 1.3 2002/11/29 17:35:09 ru Exp $ .\" .Dd August 15, 2002 .Dt MBRTOWC 3 .Os .Sh NAME .Nm mbrtowc .Nd "convert a character to a wide-character code (restartable)" .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In wchar.h .Ft size_t .Fo mbrtowc .Fa "wchar_t * restrict pwc" "const char * restrict s" "size_t n" .Fa "mbstate_t * restrict ps" .Fc .Sh DESCRIPTION The .Fn mbrtowc function inspects at most .Fa n bytes pointed to by .Fa s and interprets them as a multibyte character sequence according to the current setting of .Ev LC_CTYPE . If .Fa pwc is not .Dv NULL , the multibyte character which .Fa s represents is stored in the .Vt wchar_t it points to. .Pp If .Fa s is .Dv NULL , .Fn mbrtowc behaves as if .Fa pwc was .Dv NULL , .Fa s was an empty string .Pq Qq and .Fa n was 1. .Pp The .Vt mbstate_t argument, .Fa ps , is used to keep track of the shift state. If it is .Dv NULL , .Fn mbrtowc uses an internal, static .Vt mbstate_t object. .Sh RETURN VALUES The .Fn mbrtowc functions returns: .Bl -tag -width indent .It 0 The first .Fa n or fewer bytes of .Fa s represent the null wide character .Pq Li "L'\e0'" . .It >0 The first .Fa n or fewer bytes of .Fa s represent a valid character, .Fn mbrtowc returns the length (in bytes) of the multibyte sequence. .It Po Vt size_t Pc Ns \-2 The first .Fa n bytes of .Fa s are an incomplete multibyte sequence. .It Po Vt size_t Pc Ns \-1 The byte sequence pointed to by .Fa s is an invalid multibyte sequence. .El .Sh ERRORS The .Fn mbrtowc function will fail if: .Bl -tag -width Er .\".It Bq Er EINVAL .\"Invalid argument. .It Bq Er EILSEQ An invalid multibyte sequence was detected. .El .Sh SEE ALSO .Xr mbtowc 3 , .Xr setlocale 3 , .Xr wcrtomb 3 .Sh STANDARDS The .Fn mbrtowc function conforms to .St -isoC-99 . .Sh BUGS The current implementation does not support shift states.