#include int strcasecmp(const char *s1, const char *s2) { int c1, c2; do { c1 = tolower(*s1++); c2 = tolower(*s2++); } while (c1 == c2 && c1 != 0); return c1 - c2; } int strncasecmp(const char *s1, const char *s2, int n) { int c1, c2; do { c1 = tolower(*s1++); c2 = tolower(*s2++); } while ((--n > 0) && c1 == c2 && c1 != 0); return c1 - c2; }