Minix1.5/lib/string/strlen.x

/* strlen.x
 *	size_t strlen(const char *s)
 *
 *	Returns the length of the string pointed to by s.
 */

.define	_strlen
.text
_strlen:
	mov	bx,di		/* save di */
	mov	di,sp
	mov	di,2(di)
	mov	cx,#-1
	xorb	al,al
	cld
	repne
	scab
	not	cx		/* silly trick gives length (including null) */
	dec	cx		/* forget about null */
	mov	ax,cx
	mov	di,bx		/* restore di */
	ret