STRCASECMP(3) BSD Programmer's Manual STRCASECMP(3)
strcasecmp, strncasecmp - compare strings, ignoring case
#include <string.h> int strcasecmp(const char *s1, const char *s2); int strncasecmp(const char *s1, const char *s2, size_t len);
The strcasecmp() and strncasecmp() functions compare the NUL-terminated strings s1 and s2 and return an integer greater than, equal to, or less than 0, according to whether 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'. strncasecmp() compares at most len characters.
bcmp(3), memcmp(3), strcmp(3), strcoll(3), strxfrm(3)
The strcasecmp() and strncasecmp() functions first appeared in 4.4BSD. MirBSD #10-current June 9, 1993 1