1 .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
3 .\" %%%LICENSE_START(VERBATIM)
4 .\" Permission is granted to make and distribute verbatim copies of this
5 .\" manual provided the copyright notice and this permission notice are
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8 .\" Permission is granted to copy and distribute modified versions of this
9 .\" manual under the conditions for verbatim copying, provided that the
10 .\" entire resulting derived work is distributed under the terms of a
11 .\" permission notice identical to this one.
13 .\" Since the Linux kernel and libraries are constantly changing, this
14 .\" manual page may be incorrect or out-of-date. The author(s) assume no
15 .\" responsibility for errors or omissions, or for damages resulting from
16 .\" the use of the information contained herein. The author(s) may not
17 .\" have taken the same level of care in the production of this manual,
18 .\" which is licensed free of charge, as they might when working
21 .\" Formatted or processed versions of this manual, if unaccompanied by
22 .\" the source, must acknowledge the copyright and authors of this work.
25 .\" References consulted:
26 .\" Linux libc source code
27 .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
29 .\" Modified Sat Jul 24 18:12:45 1993 by Rik Faith (faith@cs.unc.edu)
30 .TH STRCASECMP 3 2017-09-15 "" "Linux Programmer's Manual"
32 strcasecmp, strncasecmp \- compare two strings ignoring case
35 .B #include <strings.h>
37 .BI "int strcasecmp(const char *" s1 ", const char *" s2 );
39 .BI "int strncasecmp(const char *" s1 ", const char *" s2 ", size_t " n );
44 function performs a byte-by-byte comparison of the strings
48 ignoring the case of the characters.
50 less than, equal to, or greater than zero if
53 respectively, to be less than, to match, or be greater than
58 function is similar, except that it compares
71 an integer less than, equal to, or greater than zero if
73 is, after ignoring case, found to be
74 less than, to match, or be greater than
78 For an explanation of the terms used in this section, see
84 Interface Attribute Value
88 T} Thread safety MT-Safe locale
91 4.4BSD, POSIX.1-2001, POSIX.1-2008.
97 functions first appeared in 4.4BSD, where they were declared in
99 Thus, for reasons of historical compatibility, the glibc
101 header file also declares these functions, if the
103 (or, in glibc 2.19 and earlier,
105 feature test macro is defined.
107 The POSIX.1-2008 standard says of these functions:
112 category of the locale being used is from the POSIX locale,
113 these functions shall behave as if the strings had been converted
114 to lowercase and then a byte comparison performed.
115 Otherwise, the results are unspecified.