strcasecmp, strncasecmp — compare two strings ignoring case
#include <strings.h>
int
strcasecmp( |
const char *s1, |
const char *s2); |
int
strncasecmp( |
const char *s1, |
| const char *s2, | |
size_t n); |
The strcasecmp() function
performs a byte-by-byte comparison of the strings s1 and s2, ignoring the case of the
characters. It returns an integer less than, equal to, or
greater than zero if s1 is found, respectively, to
be less than, to match, or be greater than s2.
The strncasecmp() function
is similar, except that it compares no more than n bytes of s1 and s2.
The strcasecmp() and
strncasecmp() functions return
an integer less than, equal to, or greater than zero if
s1 is, after ignoring
case, found to be less than, to match, or be greater than
s2, respectively.
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
strcasecmp(), strncasecmp() |
Thread safety | MT-Safe locale |
The strcasecmp() and
strncasecmp() functions first
appeared in 4.4BSD, where they were declared in <string.h>
Thus, for reasons of historical compatibility, the glibc
<string.h>
header file also declares these functions, if the
_DEFAULT_SOURCE (or, in glibc
2.19 and earlier, _BSD_SOURCE)
feature test macro is defined.
The POSIX.1-2008 standard says of these functions:
When the
LC_CTYPEcategory of the locale being used is from the POSIX locale, these functions shall behave as if the strings had been converted to lowercase and then a byte comparison performed. Otherwise, the results are unspecified.
bcmp(3), memcmp(3), strcmp(3), strcoll(3), string(3), strncmp(3), wcscasecmp(3), wcsncasecmp(3)
This page is part of release 5.11 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END References consulted: Linux libc source code Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) 386BSD man pages Modified Sat Jul 24 18:12:45 1993 by Rik Faith (faithcs.unc.edu) |