xref: /freebsd/lib/libc/locale/wcsrtombs.3 (revision 42249ef2)
1.\" Copyright (c) 2002-2004 Tim J. Robbins
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25.\" $FreeBSD$
26.\"
27.Dd July 21, 2004
28.Dt WCSRTOMBS 3
29.Os
30.Sh NAME
31.Nm wcsrtombs ,
32.Nm wcsnrtombs
33.Nd "convert a wide-character string to a character string (restartable)"
34.Sh LIBRARY
35.Lb libc
36.Sh SYNOPSIS
37.In wchar.h
38.Ft size_t
39.Fo wcsrtombs
40.Fa "char * restrict dst" "const wchar_t ** restrict src"
41.Fa "size_t len" "mbstate_t * restrict ps"
42.Fc
43.Ft size_t
44.Fo wcsnrtombs
45.Fa "char * restrict dst" "const wchar_t ** restrict src" "size_t nwc"
46.Fa "size_t len" "mbstate_t * restrict ps"
47.Fc
48.Sh DESCRIPTION
49The
50.Fn wcsrtombs
51function converts a string of wide characters indirectly pointed to by
52.Fa src
53to a corresponding multibyte character string stored in the array
54pointed to by
55.Fa dst .
56No more than
57.Fa len
58bytes are written to
59.Fa dst .
60.Pp
61If
62.Fa dst
63is
64.Dv NULL ,
65no characters are stored.
66.Pp
67If
68.Fa dst
69is not
70.Dv NULL ,
71the pointer pointed to by
72.Fa src
73is updated to point to the character after the one that conversion stopped at.
74If conversion stops because a null character is encountered,
75.Fa *src
76is set to
77.Dv NULL .
78.Pp
79The
80.Vt mbstate_t
81argument,
82.Fa ps ,
83is used to keep track of the shift state.
84If it is
85.Dv NULL ,
86.Fn wcsrtombs
87uses an internal, static
88.Vt mbstate_t
89object, which is initialized to the initial conversion state
90at program startup.
91.Pp
92The
93.Fn wcsnrtombs
94function behaves identically to
95.Fn wcsrtombs ,
96except that conversion stops after reading at most
97.Fa nwc
98characters from the buffer pointed to by
99.Fa src .
100.Sh RETURN VALUES
101The
102.Fn wcsrtombs
103and
104.Fn wcsnrtombs
105functions return the number of bytes stored in
106the array pointed to by
107.Fa dst
108(not including any terminating null), if successful, otherwise it returns
109.Po Vt size_t Pc Ns \-1 .
110.Sh ERRORS
111The
112.Fn wcsrtombs
113and
114.Fn wcsnrtombs
115functions will fail if:
116.Bl -tag -width Er
117.It Bq Er EILSEQ
118An invalid wide character was encountered.
119.It Bq Er EINVAL
120The conversion state is invalid.
121.El
122.Sh SEE ALSO
123.Xr mbsrtowcs 3 ,
124.Xr wcrtomb 3 ,
125.Xr wcstombs 3
126.Sh STANDARDS
127The
128.Fn wcsrtombs
129function conforms to
130.St -isoC-99 .
131.Pp
132The
133.Fn wcsnrtombs
134function is an extension to the standard.
135