locale/mbtowc.3

   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: src/lib/libc/locale/mbtowc.3,v 1.5 2007/01/09 00:28:00 imp Exp $
  35 .\"
  36 .Dd April 11, 2004
  37 .Dt MBTOWC 3
  38 .Os
  39 .Sh NAME
  40 .Nm mbtowc ,
  41 .Nm mbtowc_l
  42 .Nd convert a character to a wide-character code
  43 .Sh LIBRARY
  44 .Lb libc
  45 .Sh SYNOPSIS
  46 .In stdlib.h
  47 .Ft int
  48 .Fo mbtowc
  49 .Fa "wchar_t *restrict pwc"
  50 .Fa "const char *restrict s"
  51 .Fa "size_t n"
  52 .Fc
  53 .In stdlib.h
  54 .In xlocale.h
  55 .Ft int
  56 .Fo mbtowc_l
  57 .Fa "wchar_t *restrict pwc"
  58 .Fa "const char *restrict s"
  59 .Fa "size_t n"
  60 .Fa "locale_t loc"
  61 .Fc
  62 .Sh DESCRIPTION
  63 The
  64 .Fn mbtowc
  65 function converts a multibyte character
  66 .Fa s
  67 into a wide character, according to the current conversion state,
  68 and stores the result
  69 in the object pointed to by
  70 .Fa pwc .
  71 Up to
  72 .Fa n
  73 bytes are examined.
  74 .Pp
  75 A call with a null
  76 .Fa s
  77 pointer returns nonzero if the current encoding requires shift states,
  78 zero otherwise;
  79 if shift states are required, the shift state is reset to the initial state.
  80 .Pp
  81 While the
  82 .Fn mbtowc
  83 function uses the current locale, the
  84 .Fn mbtowc_l
  85 function may be passed a locale directly. See
  86 .Xr xlocale 3
  87 for more information.
  88 .Sh RETURN VALUES
  89 If
  90 .Fa s
  91 is
  92 .Dv NULL ,
  93 the
  94 .Fn mbtowc
  95 function returns nonzero if shift states are supported,
  96 zero otherwise.
  97 .Pp
  98 Otherwise, if
  99 .Fa s
 100 is not a null pointer,
 101 .Fn mbtowc
 102 either returns 0 if
 103 .Fa s
 104 represents the null wide character, or returns
 105 the number of bytes processed in
 106 .Fa s ,
 107 or returns \-1 if no multibyte character
 108 could be recognized or converted.
 109 In this case,
 110 .Fn mbtowc Ns 's
 111 internal conversion state is undefined.
 112 .Sh ERRORS
 113 The
 114 .Fn mbtowc
 115 function will fail if:
 116 .Bl -tag -width Er
 117 .It Bq Er EILSEQ
 118 An invalid multibyte sequence was detected.
 119 .It Bq Er EINVAL
 120 The internal conversion state is invalid.
 121 .El
 122 .Sh SEE ALSO
 123 .Xr btowc 3 ,
 124 .Xr mblen 3 ,
 125 .Xr mbrtowc 3 ,
 126 .Xr mbstowcs 3 ,
 127 .Xr multibyte 3 ,
 128 .Xr wctomb 3 ,
 129 .Xr xlocale 3
 130 .Sh STANDARDS
 131 The
 132 .Fn mbtowc
 133 function conforms to
 134 .St -isoC-99 .