summaryrefslogtreecommitdiff
path: root/src/lib/libc/string/strtok.3
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/libc/string/strtok.3')
-rw-r--r--src/lib/libc/string/strtok.3152
1 files changed, 152 insertions, 0 deletions
diff --git a/src/lib/libc/string/strtok.3 b/src/lib/libc/string/strtok.3
new file mode 100644
index 0000000000..bdf28f68f6
--- /dev/null
+++ b/src/lib/libc/string/strtok.3
@@ -0,0 +1,152 @@
1.\" Copyright (c) 1988, 1991 The Regents of the University of California.
2.\" All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" the American National Standards Committee X3, on Information
6.\" Processing Systems.
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.\" 3. 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.\" $OpenBSD: strtok.3,v 1.16 2003/06/02 20:18:38 millert Exp $
33.\"
34.Dd June 29, 1991
35.Dt STRTOK 3
36.Os
37.Sh NAME
38.Nm strtok ,
39.Nm strtok_r
40.Nd string token operations
41.Sh SYNOPSIS
42.Fd #include <string.h>
43.Ft char *
44.Fn strtok "char *str" "const char *sep"
45.Ft char *
46.Fn strtok_r "char *str" "const char *sep" "char **last"
47.Sh DESCRIPTION
48.Bf -symbolic
49This interface is obsoleted by
50.Xr strsep 3 .
51.Ef
52.Pp
53The
54.Fn strtok
55function is used to isolate sequential tokens in a null-terminated string,
56.Fa str .
57These tokens are separated in the string by at least one of the
58characters in
59.Fa sep .
60The first time that
61.Fn strtok
62is called,
63.Fa str
64should be specified; subsequent calls, wishing to obtain further tokens
65from the same string, should pass a null pointer instead.
66The separator string,
67.Fa sep ,
68must be supplied each time, and may change between calls.
69.Pp
70The
71.Fn strtok_r
72function is a version of
73.Fn strtok
74that takes an explicit context argument and is reentrant.
75.Pp
76The
77.Fn strtok
78and
79.Fn strtok_r
80functions return a pointer to the beginning of each subsequent token
81in the string, after replacing the separator character itself with an
82.Tn ASCII NUL
83character.
84When no more tokens remain, a null pointer is returned.
85.Pp
86Since
87.Fn strtok
88and
89.Fn strtok_r
90modify the string,
91.Fa str
92should not point to an area in the initialized data segment.
93.Sh EXAMPLES
94The following will construct an array of pointers to each individual word in
95the string
96.Va s :
97.Bd -literal -offset indent
98#define MAXTOKENS 128
99
100char s[512], *p, *tokens[MAXTOKENS];
101char *last;
102int i = 0;
103
104snprintf(s, sizeof(s), "cat dog horse cow");
105
106for ((p = strtok_r(s, " ", &last)); p;
107 (p = strtok_r(NULL, " ", &last)), i++) {
108 if (i < MAXTOKENS - 1)
109 tokens[i] = p;
110}
111tokens[i] = NULL;
112.Ed
113.Pp
114That is,
115.Li tokens[0]
116will point to
117.Qq cat ,
118.Li tokens[1]
119will point to
120.Qq dog ,
121.Li tokens[2]
122will point to
123.Qq horse ,
124and
125.Li tokens[3]
126will point to
127.Qq cow .
128.Sh SEE ALSO
129.Xr memchr 3 ,
130.Xr strchr 3 ,
131.Xr strcspn 3 ,
132.Xr strpbrk 3 ,
133.Xr strrchr 3 ,
134.Xr strsep 3 ,
135.Xr strspn 3 ,
136.Xr strstr 3
137.Sh STANDARDS
138The
139.Fn strtok
140function conforms to
141.St -ansiC .
142.Sh BUGS
143The System V
144.Fn strtok ,
145if handed a string containing only delimiter characters,
146will not alter the next starting point, so that a call to
147.Fn strtok
148with a different (or empty) delimiter string
149may return a non-null value.
150Since this implementation always alters the next starting point,
151such a sequence of calls would always return
152.Dv NULL .