/* * Concatenate s2 on the end of s1.  S1's space must be large enough. * At most n characters are moved. * Return s1. */char *strncat(s1, s2, n)register char *s1, *s2;register n;{	register char *os1;	os1 = s1;	while (*s1++)		;	--s1;	while (*s1++ = *s2++)		if (--n < 0) {			*--s1 = '\0';			break;		}	return(os1);}