osx man page for strncasecmp

STRCASECMP(3)						   BSD Library Functions Manual 					     STRCASECMP(3)

NAME
     strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l -- compare strings, ignoring case

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <strings.h>

     int
     strcasecmp(const char *s1, const char *s2);

     int
     strncasecmp(const char *s1, const char *s2, size_t n);

     #include <strings.h>
     #include <xlocale.h>

     int
     strcasecmp_l(const char *s1, const char *s2, locale_t loc);

     int
     strncasecmp_l(const char *s1, const char *s2, size_t n, locale_t loc);

DESCRIPTION
     The strcasecmp() and strncasecmp() functions compare the null-terminated strings s1 and s2.

     The strncasecmp() compares at most n characters.

     Although the strcasecmp() and strncasecmp() functions use the current locale, the strcasecmp_l() and strncasecmp_l() functions may be passed
     locales directly. See xlocale(3) for more information.

RETURN VALUES
     The strcasecmp() and strncasecmp() return an integer greater than, equal to, or less than 0, according as s1 is lexicographically greater
     than, equal to, or less than s2 after translation of each corresponding character to lower-case.  The strings themselves are not modified.
     The comparison is done using unsigned characters, so that '200' is greater than ''.

SEE ALSO
     bcmp(3), memcmp(3), strcmp(3), strcoll(3), strxfrm(3), tolower(3), xlocale(3)

HISTORY
     The strcasecmp() and strncasecmp() functions first appeared in 4.4BSD.  Their prototypes existed previously in <string.h> before they were
     moved to <strings.h> for IEEE Std 1003.1-2001 (``POSIX.1'') compliance.

BSD
								   June 9, 1993 							       BSD