#include <ctype.h>
#include <string.h>

char *strcasestr(const char *h, const char *n)
{
	size_t i, l = strlen(n);
	for (; *h; h++) {
		for (i = 0; i < l && tolower((unsigned char)n[i]) == tolower((unsigned char)h[i]); ++i);
		if (i == l) return (char *)h;
	}
	return 0;
}