xref: /openbsd-src/lib/libc/string/strcasecmp.3 (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1.\" $OpenBSD: strcasecmp.3,v 1.6 2000/04/21 15:24:19 aaron Exp $
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6.\" This code is derived from software contributed to Berkeley by
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36.\"     @(#)strcasecmp.3	8.1 (Berkeley) 6/9/93
37.\"
38.Dd June 9, 1993
39.Dt STRCASECMP 3
40.Os
41.Sh NAME
42.Nm strcasecmp ,
43.Nm strncasecmp
44.Nd compare strings, ignoring case
45.Sh SYNOPSIS
46.Fd #include <string.h>
47.Ft int
48.Fn strcasecmp "const char *s1" "const char *s2"
49.Ft int
50.Fn strncasecmp "const char *s1" "const char *s2" "size_t len"
51.Sh DESCRIPTION
52The
53.Fn strcasecmp
54and
55.Fn strncasecmp
56functions compare the null-terminated strings
57.Fa s1
58and
59.Fa s2
60and return an integer greater than, equal to, or less than 0,
61according as
62.Fa s1
63is lexicographically greater than, equal to, or less than
64.Fa s2
65after translation of each corresponding character to lower-case.
66The strings themselves are not modified.
67The comparison is done using unsigned characters, so that
68.Sq Li \e200
69is greater than
70.Ql \e0 .
71.Pp
72.Fn strncasecmp
73compares at most
74.Fa len
75characters.
76.Sh SEE ALSO
77.Xr bcmp 3 ,
78.Xr memcmp 3 ,
79.Xr strcmp 3 ,
80.Xr strcoll 3 ,
81.Xr strxfrm 3
82.Sh HISTORY
83The
84.Fn strcasecmp
85and
86.Fn strncasecmp
87functions first appeared in
88.Bx 4.4 .
89