xref: /freebsd/lib/libc/string/wcstok.3 (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1.\" Copyright (c) 1998 Softweyr LLC.  All rights reserved.
2.\"
3.\" strtok_r, from Berkeley strtok
4.\" Oct 13, 1998 by Wes Peters <wes@softweyr.com>
5.\"
6.\" Copyright (c) 1988, 1991, 1993
7.\"	The Regents of the University of California.  All rights reserved.
8.\"
9.\" This code is derived from software contributed to Berkeley by
10.\" the American National Standards Committee X3, on Information
11.\" Processing Systems.
12.\"
13.\" Redistribution and use in source and binary forms, with or without
14.\" modification, are permitted provided that the following conditions
15.\" are met:
16.\"
17.\" 1. Redistributions of source code must retain the above copyright
18.\"    notices, this list of conditions and the following disclaimer.
19.\"
20.\" 2. Redistributions in binary form must reproduce the above
21.\"    copyright notices, this list of conditions and the following
22.\"    disclaimer in the documentation and/or other materials provided
23.\"    with the distribution.
24.\"
25.\" 3. All advertising materials mentioning features or use of this
26.\"    software must display the following acknowledgement:
27.\"
28.\"	This product includes software developed by Softweyr LLC, the
29.\"      University of California, Berkeley, and its contributors.
30.\"
31.\" 4. Neither the name of Softweyr LLC, the University nor the names
32.\"    of its contributors may be used to endorse or promote products
33.\"    derived from this software without specific prior written
34.\"    permission.
35.\"
36.\" THIS SOFTWARE IS PROVIDED BY SOFTWEYR LLC, THE REGENTS AND
37.\" CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
38.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
39.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
40.\" DISCLAIMED.  IN NO EVENT SHALL SOFTWEYR LLC, THE REGENTS, OR
41.\" CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
44.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
45.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
47.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48.\" SUCH DAMAGE.
49.\"
50.Dd October 3, 2002
51.Dt WCSTOK 3
52.Os
53.Sh NAME
54.Nm wcstok
55.Nd split wide-character string into tokens
56.Sh LIBRARY
57.Lb libc
58.Sh SYNOPSIS
59.In wchar.h
60.Ft wchar_t *
61.Fn wcstok "wchar_t * restrict str" "const wchar_t * restrict sep" "wchar_t ** restrict last"
62.Sh DESCRIPTION
63The
64.Fn wcstok
65function
66is used to isolate sequential tokens in a null-terminated wide character
67string,
68.Fa str .
69These tokens are separated in the string by at least one of the
70characters in
71.Fa sep .
72The first time that
73.Fn wcstok
74is called,
75.Fa str
76should be specified; subsequent calls, wishing to obtain further tokens
77from the same string, should pass a null pointer instead.
78The separator string,
79.Fa sep ,
80must be supplied each time, and may change between calls.
81The context pointer
82.Fa last
83must be provided on each call.
84.Pp
85The
86.Fn wcstok
87function is the wide character counterpart of the
88.Fn strtok_r
89function.
90.Sh RETURN VALUES
91The
92.Fn wcstok
93function
94returns a pointer to the beginning of each subsequent token in the string,
95after replacing the token itself with a null wide character (L'\e0').
96When no more tokens remain, a null pointer is returned.
97.Sh EXAMPLES
98The following code fragment splits a wide character string on
99.Tn ASCII
100space, tab and newline characters and writes the tokens to
101standard output:
102.Bd -literal -offset indent
103const wchar_t *seps = L" \et\en";
104wchar_t *last, *tok, text[] = L" \enone\ettwo\et\etthree  \en";
105
106for (tok = wcstok(text, seps, &last); tok != NULL;
107    tok = wcstok(NULL, seps, &last))
108	wprintf(L"%ls\en", tok);
109.Ed
110.Sh COMPATIBILITY
111Some early implementations of
112.Fn wcstok
113omit the
114context pointer argument,
115.Fa last ,
116and maintain state across calls in a static variable like
117.Fn strtok
118does.
119.Sh SEE ALSO
120.Xr strtok 3 ,
121.Xr wcschr 3 ,
122.Xr wcscspn 3 ,
123.Xr wcspbrk 3 ,
124.Xr wcsrchr 3 ,
125.Xr wcsspn 3
126.Sh STANDARDS
127The
128.Fn wcstok
129function
130conforms to
131.St -isoC-99 .
132