strcasecmp(3) Library Functions Manual strcasecmp(3) strcasecmp, strncasecmp - (libc -lc) #include int strcasecmp(const char *s1, const char *s2); int strncasecmp(const char s1[], const char s2[], size_t n); strcasecmp() s1 s2 . s1 s2. strncasecmp() n s1 s2. strcasecmp() strncasecmp() s1 s2 . attributes(7). +----------------------+------------------------------------+---------------------------------------------------------------------------------------------+ | | | | +----------------------+------------------------------------+---------------------------------------------------------------------------------------------+ |strcasecmp() | | (locale) (MT-Safe) | |strncasecmp() | | | +----------------------+------------------------------------+---------------------------------------------------------------------------------------------+ POSIX.1-2008. 4.4BSD POSIX.1-2001. strcasecmp() strncasecmp() 4.4BSD . glibc _DEFAULT_SOURCE ( glibc 2.19 _BSD_SOURCE). POSIX.1-2008 : LC_CTYPE POSIX . . memcmp(3) strcmp(3) strcoll(3) string(3) strncmp(3) wcscasecmp(3) wcsncasecmp(3) 3 . . : . 6.18 8 2026 strcasecmp(3)