xref: /freebsd/lib/libc/locale/mbsrtowcs.3 (revision 8b8109275c1a583e96171df08e3136151c02279e)
1.\" Copyright (c) 2002-2004 Tim J. Robbins
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25.\" $FreeBSD$
26.Dd April 8, 2004
27.Dt MBSRTOWCS 3
28.Os
29.Sh NAME
30.Nm mbsrtowcs
31.Nd "convert a character string to a wide-character string (restartable)"
32.Sh LIBRARY
33.Lb libc
34.Sh SYNOPSIS
35.In wchar.h
36.Ft size_t
37.Fo mbsrtowcs
38.Fa "wchar_t * restrict dst" "const char ** restrict src" "size_t len"
39.Fa "mbstate_t * restrict ps"
40.Fc
41.Sh DESCRIPTION
42The
43.Fn mbsrtowcs
44function converts a sequence of multibyte characters pointed to indirectly by
45.Fa src
46into a sequence of corresponding wide characters and stores at most
47.Fa len
48of them in the
49.Vt wchar_t
50array pointed to by
51.Fa dst ,
52until it encounters a terminating null character
53.Pq Li '\e0' .
54.Pp
55If
56.Fa dst
57is
58.Dv NULL ,
59no characters are stored.
60.Pp
61If
62.Fa dst
63is not
64.Dv NULL ,
65the pointer pointed to by
66.Fa src
67is updated to point to the character after the one that conversion stopped at.
68If conversion stops because a null character is encountered,
69.Fa *src
70is set to
71.Dv NULL .
72.Pp
73The
74.Vt mbstate_t
75argument,
76.Fa ps ,
77is used to keep track of the shift state.
78If it is
79.Dv NULL ,
80.Fn mbsrtowcs
81uses an internal, static
82.Vt mbstate_t
83object, which is initialized to the initial conversion state
84at program startup.
85.Sh RETURN VALUES
86The
87.Fn mbsrtowcs
88function returns the number of wide characters stored in
89the array pointed to by
90.Fa dst
91if successful, otherwise it returns
92.Po Vt size_t Pc Ns \-1 .
93.Sh ERRORS
94The
95.Fn mbsrtowcs
96function will fail if:
97.Bl -tag -width Er
98.It Bq Er EILSEQ
99An invalid multibyte character sequence was encountered.
100.It Bq Er EINVAL
101The conversion state is invalid.
102.El
103.Sh SEE ALSO
104.Xr mbrtowc 3 ,
105.Xr mbstowcs 3 ,
106.Xr multibyte 3 ,
107.Xr wcsrtombs 3
108.Sh STANDARDS
109The
110.Fn mbsrtowcs
111function conforms to
112.St -isoC-99 .
113