freebsd man page for strcasecmp

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

NAME
     strcasecmp, strncasecmp -- 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 len);

     #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 len, locale_t loc);

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

     The strncasecmp() function compares at most len characters.  The strcasecmp_l() and strncasecmp_l() functions do the same as their non-locale
     versions above, but take an explicit locale rather than using the current locale.

RETURN VALUES
     The functions strcasecmp() and strncasecmp() return an integer greater than, equal to, or less than 0, depending on whether s1 is lexico-
     graphically 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 ''.	The functions strcasecmp_l() and
     strncasecmp_l() do the same but take explicit locales.

SEE ALSO
     bcmp(3), memcmp(3), strcmp(3), strcoll(3), strxfrm(3), tolower(3), wcscasecmp(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
								   May 29, 2014 							       BSD