xref: /freebsd/lib/libc/string/strchr.3 (revision 848ee2a3a8b47c9905fc51fefcf60eb371edbb98)
1.\" Copyright (c) 1990, 1991, 1993
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" Chris Torek and the American National Standards Committee X3,
6.\" on Information 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.\"     @(#)strchr.3	8.2 (Berkeley) 4/19/94
33.\" $FreeBSD$
34.\"
35.Dd February 13, 2013
36.Dt STRCHR 3
37.Os
38.Sh NAME
39.Nm strchr , strrchr , strchrnul
40.Nd locate character in string
41.Sh LIBRARY
42.Lb libc
43.Sh SYNOPSIS
44.In string.h
45.Ft "char *"
46.Fn strchr "const char *s" "int c"
47.Ft "char *"
48.Fn strrchr "const char *s" "int c"
49.Ft "char *"
50.Fn strchrnul "const char *s" "int c"
51.Sh DESCRIPTION
52The
53.Fn strchr
54function locates the first occurrence of
55.Fa c
56(converted to a
57.Vt char )
58in the string pointed to by
59.Fa s .
60The terminating null character is considered part of the string;
61therefore if
62.Fa c
63is
64.Ql \e0 ,
65the functions locate the terminating
66.Ql \e0 .
67.Pp
68The
69.Fn strrchr
70function is identical to
71.Fn strchr
72except it locates the last occurrence of
73.Fa c .
74.Pp
75The
76.Fn strchrnul
77function is identical to
78.Fn strchr
79except that if
80.Fa c
81is not found in
82.Fa s
83a pointer to the terminating
84.Ql \e0
85is returned.
86.Sh RETURN VALUES
87The functions
88.Fn strchr
89and
90.Fn strrchr
91return a pointer to the located character, or
92.Dv NULL
93if the character does not appear in the string.
94.Pp
95.Fn strchrnul
96returns a pointer to the terminating
97.Ql \e0
98if the character does not appear in the string.
99.Sh SEE ALSO
100.Xr memchr 3 ,
101.Xr memmem 3 ,
102.Xr strcspn 3 ,
103.Xr strpbrk 3 ,
104.Xr strsep 3 ,
105.Xr strspn 3 ,
106.Xr strstr 3 ,
107.Xr strtok 3 ,
108.Xr wcschr 3
109.Sh STANDARDS
110The functions
111.Fn strchr
112and
113.Fn strrchr
114conform to
115.St -isoC .
116The function
117.Fn strchrnul
118is a
119.Tn GNU
120extension.
121.Sh HISTORY
122The
123.Fn strchrnul
124function first appeared in glibc 2.1.1 and was added in
125.Fx 10.0 .
126