xref: /dragonfly/lib/libc/string/strcmp.3 (revision 7ff0fc30)
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.\"     @(#)strcmp.3	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD: head/lib/libc/string/strcmp.3 251069 2013-05-28 20:57:40Z emaste $
34.\"
35.Dd October 11, 2001
36.Dt STRCMP 3
37.Os
38.Sh NAME
39.Nm strcmp ,
40.Nm strncmp
41.Nd compare strings
42.Sh LIBRARY
43.Lb libc
44.Sh SYNOPSIS
45.In string.h
46.Ft int
47.Fn strcmp "const char *s1" "const char *s2"
48.Ft int
49.Fn strncmp "const char *s1" "const char *s2" "size_t len"
50.Sh DESCRIPTION
51The
52.Fn strcmp
53and
54.Fn strncmp
55functions
56lexicographically compare the null-terminated strings
57.Fa s1
58and
59.Fa s2 .
60.Pp
61The
62.Fn strncmp
63function
64compares not more than
65.Fa len
66characters.
67Because
68.Fn strncmp
69is designed for comparing strings rather than binary data,
70characters that appear after a
71.Ql \e0
72character are not compared.
73.Sh RETURN VALUES
74The
75.Fn strcmp
76and
77.Fn strncmp
78functions return an integer greater than, equal to, or less than 0, according
79as the string
80.Fa s1
81is greater than, equal to, or less than the string
82.Fa s2 .
83The comparison is done using unsigned characters, so that
84.Ql \e200
85is greater than
86.Ql \e0 .
87.Sh SEE ALSO
88.Xr memcmp 3 ,
89.Xr strcasecmp 3 ,
90.Xr strcoll 3 ,
91.Xr strxfrm 3 ,
92.Xr wcscmp 3
93.Sh STANDARDS
94The
95.Fn strcmp
96and
97.Fn strncmp
98functions
99conform to
100.St -isoC .
101