xref: /freebsd/lib/libc/string/strcmp.3 (revision 1dfcff294e44d4b45813288ef4095c36abb22f0e)
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32.\"     @(#)strcmp.3	8.1 (Berkeley) 6/4/93
33.\" $FreeBSD$
34.\"
35.Dd April 3, 2022
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 bcmp 3 ,
89.Xr memcmp 3 ,
90.Xr strcasecmp 3 ,
91.Xr strcoll 3 ,
92.Xr strxfrm 3 ,
93.Xr wcscmp 3
94.Sh STANDARDS
95The
96.Fn strcmp
97and
98.Fn strncmp
99functions
100conform to
101.St -isoC .
102.Sh HISTORY
103The
104.Fn strcmp
105function first appeared in the Programmer's Workbench (PWB/UNIX)
106and was ported to
107.At v7 ;
108.Fn strncmp
109first appeared in
110.At v7 .
111