1 .\" Copyright (c) 2001 Mike Barcroft <mike@FreeBSD.org>
2 .\" Copyright (c) 1990, 1991, 1993
3 .\" The Regents of the University of California. All rights reserved.
5 .\" This code is derived from software contributed to Berkeley by
6 .\" Chris Torek and the American National Standards Committee X3,
7 .\" on Information Processing Systems.
9 .\" Redistribution and use in source and binary forms, with or without
10 .\" modification, are permitted provided that the following conditions
12 .\" 1. Redistributions of source code must retain the above copyright
13 .\" notice, this list of conditions and the following disclaimer.
14 .\" 2. Redistributions in binary form must reproduce the above copyright
15 .\" notice, this list of conditions and the following disclaimer in the
16 .\" documentation and/or other materials provided with the distribution.
17 .\" 4. Neither the name of the University nor the names of its contributors
18 .\" may be used to endorse or promote products derived from this software
19 .\" without specific prior written permission.
21 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 .\" @(#)strstr.3 8.1 (Berkeley) 6/4/93
34 .\" $FreeBSD: src/lib/libc/string/strstr.3,v 1.14 2007/01/09 00:28:12 imp Exp $
35 .\" $DragonFly: src/lib/libc/string/strstr.3,v 1.5 2005/08/05 22:35:10 swildner Exp $
44 .Nd locate a substring in a string
50 .Fn strstr "const char *big" "const char *little"
52 .Fn strcasestr "const char *big" "const char *little"
54 .Fn strnstr "const char *big" "const char *little" "size_t len"
59 locates the first occurrence of the null-terminated string
61 in the null-terminated string
66 function is similar to
68 but ignores the case of both strings.
73 locates the first occurrence of the null-terminated string
79 characters are searched.
80 Characters that appear after a
82 character are not searched.
89 specific API, it should only be used when portability is not a concern.
102 otherwise a pointer to the first character of the first occurrence of
106 The following sets the pointer
112 .Bd -literal -offset indent
113 const char *largestring = "Foo Bar Baz";
114 const char *smallstring = "Bar";
117 ptr = strstr(largestring, smallstring);
120 The following sets the pointer
124 because only the first 4 characters of
127 .Bd -literal -offset indent
128 const char *largestring = "Foo Bar Baz";
129 const char *smallstring = "Bar";
132 ptr = strnstr(largestring, smallstring, 4);