xref: /dragonfly/lib/libc/string/strcasecmp.3 (revision c3762235)
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30.\"     @(#)strcasecmp.3	8.1 (Berkeley) 6/9/93
31.\" $FreeBSD: head/lib/libc/string/strcasecmp.3 251069 2013-05-28 20:57:40Z emaste $
32.\"
33.Dd December 25, 2013
34.Dt STRCASECMP 3
35.Os
36.Sh NAME
37.Nm strcasecmp ,
38.Nm strncasecmp
39.Nd compare strings, ignoring case
40.Sh LIBRARY
41.Lb libc
42.Sh SYNOPSIS
43.In strings.h
44.Ft int
45.Fn strcasecmp "const char *s1" "const char *s2"
46.Ft int
47.Fn strncasecmp "const char *s1" "const char *s2" "size_t len"
48.Ft int
49.Fn strcasecmp_l "const char *s1" "const char *s2" "locale_t locale"
50.Ft int
51.Fn strncasecmp_l "const char *s1" "const char *s2" "size_t len" "locale_t locale"
52.Sh DESCRIPTION
53The
54.Fn strcasecmp ,
55.Fn strcasecmp_l ,
56.Fn strncasecmp ,
57and
58.Fn strncasecmp_l
59functions
60compare the null-terminated strings
61.Fa s1
62and
63.Fa s2 .
64.Pp
65The
66.Fn strncasecmp
67function compares at most
68.Fa len
69characters.
70The
71.Fn strcasecmp_l
72and
73.Fn strncasecmp_l
74functions do the same as their non-locale versions above, but take an
75explicit
76.Fa locale
77rather than using the current locale.
78.Sh RETURN VALUES
79The functions
80.Fn strcasecmp
81and
82.Fn strncasecmp
83return an integer greater than, equal to, or less than 0,
84depending on whether
85.Fa s1
86is lexicographically greater than, equal to, or less than
87.Fa s2
88after translation of each corresponding character to lower-case.
89The strings themselves are not modified.
90The comparison is done using unsigned characters, so that
91.Sq Li \e200
92is greater than
93.Ql \e0 .
94The functions
95.Fn strcasecmp_l
96and
97.Fn strncasecmp_l
98do the same but take explicit locales.
99.Sh SEE ALSO
100.Xr bcmp 3 ,
101.Xr memcmp 3 ,
102.Xr strcmp 3 ,
103.Xr strcoll 3 ,
104.Xr strxfrm 3 ,
105.Xr tolower 3 ,
106.Xr wcscasecmp 3
107.Sh HISTORY
108The
109.Fn strcasecmp
110and
111.Fn strncasecmp
112functions first appeared in
113.Bx 4.4 .
114Their prototypes existed previously in
115.In string.h
116before they were moved to
117.In strings.h
118for
119.St -p1003.1-2001
120compliance.
121.Pp
122The
123.Fn strcasecmp_l
124and
125.Fn strncasecmp_l
126functions conform to
127.St -p1003.1-2008 .
128