STRCASECMP(3) Library Functions Manual STRCASECMP(3)

strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_lcompare strings, ignoring case

Standard C Library (libc, -lc)

#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);

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

The () compares at most n characters.

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

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 ‘\0’.

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

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.

June 9, 1993 macOS 15.2