xref: /dragonfly/lib/libc/locale/mbstowcs.3 (revision 49781055)
1.\" $NetBSD: src/lib/libc/locale/mbstowcs.3,v 1.8 2004/01/24 16:58:54 wiz Exp $
2.\" $DragonFly: src/lib/libc/locale/mbstowcs.3,v 1.1 2005/03/12 00:18:01 joerg Exp $
3.\"
4.\" Copyright (c)2002 Citrus Project,
5.\" All rights reserved.
6.\"
7.\" Redistribution and use in source and binary forms, with or without
8.\" modification, are permitted provided that the following conditions
9.\" are met:
10.\" 1. Redistributions of source code must retain the above copyright
11.\"    notice, this list of conditions and the following disclaimer.
12.\" 2. Redistributions in binary form must reproduce the above copyright
13.\"    notice, this list of conditions and the following disclaimer in the
14.\"    documentation and/or other materials provided with the distribution.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.Dd February 3, 2002
29.Dt MBSTOWCS 3
30.Os
31.\" ----------------------------------------------------------------------
32.Sh NAME
33.Nm mbstowcs
34.Nd converts a multibyte character string to a wide character string
35.\" ----------------------------------------------------------------------
36.Sh LIBRARY
37.Lb libc
38.\" ----------------------------------------------------------------------
39.Sh SYNOPSIS
40.In stdlib.h
41.Ft size_t
42.Fn mbstowcs "wchar_t * restrict pwcs" "const char * restrict s" "size_t n"
43.\" ----------------------------------------------------------------------
44.Sh DESCRIPTION
45.Fn mbstowcs
46converts a null-terminated multibyte character string pointed to by
47.Fa s
48to the corresponding wide character string and stores it in the array
49pointed to by
50.Fa pwcs .
51This function may modify the first at most
52.Fa n
53elements of the array pointed to by
54.Fa pwcs .
55Each character will be converted as if
56.Xr mbtowc 3
57is continuously called, except the internal state of
58.Xr mbtowc 3
59will not be affected.
60.Pp
61For state-dependent encoding,
62.Fn mbstowcs
63implies the multibyte character string pointed to by
64.Fa s
65always begins with an initial state.
66.Pp
67These are the special cases:
68.Bl -tag -width 012345678901
69.It pwcs == NULL
70.Fn mbstowcs
71returns the number of elements to store the whole wide character string
72corresponding to the multibyte character string pointed to by
73.Fa s .
74In this case,
75.Fa n
76is ignored.
77.It s == NULL
78Undefined (may cause the program to crash).
79.El
80.\" ----------------------------------------------------------------------
81.Sh RETURN VALUES
82.Fn mbstowcs
83returns:
84.Bl -tag -width 012345678901
85.It 0 or positive
86Number of elements stored in the array pointed to by
87.Fa pwcs .
88There are no cases that the value returned is greater than
89.Fa n
90(unless
91.Fa pwcs
92is a null pointer) or the value of the
93.Dv MB_CUR_MAX
94macro.
95If the return value is equal to
96.Fa n ,
97the string pointed to by
98.Fa pwcs
99will not be null-terminated.
100.It (size_t)-1
101.Fa s
102points to a string containing an invalid or incomplete multibyte character.
103The
104.Fn mbstowcs
105also sets
106.Va errno
107to indicate the error.
108.El
109.\" ----------------------------------------------------------------------
110.Sh ERRORS
111.Fn mbstowcs
112may cause an error in the following case:
113.Bl -tag -width Er
114.It Bq Er EILSEQ
115.Fa s
116points to a string containing an invalid or incomplete multibyte character.
117.El
118.\" ----------------------------------------------------------------------
119.Sh SEE ALSO
120.Xr mbtowc 3 ,
121.Xr setlocale 3
122.\" ----------------------------------------------------------------------
123.Sh STANDARDS
124The
125.Fn mbstowcs
126function conforms to
127.St -ansiC .
128The restrict qualifier is added at
129.St -isoC-99 .
130