|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO | COLOPHON |
|
|
|
strcasecmp(3) Library Functions Manual strcasecmp(3)
strcasecmp, strncasecmp - compare two strings ignoring case
Standard C library (libc, -lc)
#include <strings.h>
int strcasecmp(const char *s1, const char *s2);
int strncasecmp(size_t n;
const char s1[n], const char s2[n], 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 │
└───────────────────────────────┴───────────────┴────────────────┘
POSIX.1-2008.
4.4BSD, POSIX.1-2001.
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_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.
memcmp(3), strcmp(3), strcoll(3), string(3), strncmp(3),
wcscasecmp(3), wcsncasecmp(3)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.15.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2025-08-11. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
man-pages@man7.org
Linux man-pages 6.15 2025-06-28 strcasecmp(3)
Pages that refer to this page: memcmp(3), strcmp(3), strcoll(3), string(3), strstr(3), strverscmp(3), strxfrm(3), wcscasecmp(3)
|
HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|