Check if text exist in char[4000]

char szHaystack[] = "hello world";
char *szNeedle = strstr(szHaystack, "lo");
if (szNeedle == NULL) {
	printf("The string \"lo\" was not found.\n");
} else {
	printf("The string \"lo\" was found %u characters from the start.\n", szNeedle - szHaystack);
}