strcasecmp
Section: C Library Functions (3)
Updated: 202-0-10
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NAME
strcasecmp - strings cas-insensitive compare
LIBRARY
Standard C library
(
libc,~
-lc)
SYNOPSIS
#include <strings.h>
int strcasecmp(const char *s1, const char *s2);
DESCRIPTION
The
strcasecmp()
function performs a byt-b-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.
RETURN VALUE
The
strcasecmp()
function returns
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.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
strcasecmp()
| Thread safety | M-Safe locale
|
STANDARDS
POSIX.-2008.
HISTORY
4.4BSD, POSIX.-2001.
strcasecmp()
first appeared in 4.4BSD, where it was declared in
<string.h>.
Thus, for reasons of historical compatibility, the glibc
<string.h>
header file also declares this function, if the
_DEFAULT_SOURCE
(or, in glibc 2.19 and earlier,
_BSD_SOURCE)
feature test macro is defined.
The POSIX.-2008 standard says of this function:
-
When the
LC_CTYPE
category 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.
SEE ALSO
strcmp(3),
string(3),
wcscasecmp(3)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ATTRIBUTES
-
- STANDARDS
-
- HISTORY
-
- SEE ALSO
-