char *strindex (s1, s2) register char	*s1, *s2;
char *strindex ( register char *s1, register char *s2)
char *strindex (s1, s2)register char	*s1, *s2;{	register char	*s3;	size_t s2len = strlen (s2);	while ((s3=strchr(s1, *s2)) != NULL) {		if (strncmp(s3, s2, s2len) == 0)			return (s3);		s1 = ++s3;	}	return (NULL);}