title	GETARG
	subttl	Module from library C_2 : GETARG
	maclib	SYSEQU.LIB

; FILE:	GETARG.MAC
; DATE: 820819:1533
; FOR:	Return argument # A

; Get nth argument from command line
; ENTRY	: Accu contains no. of arg to get
; EXIT	: Reg HL points to arg
;	  Accu contains ENDSTR unless arg is null

	entry	getarg

	ext	nargs,argbuf

getarg:
	push	bc
	or	a		; Check zero argument
	jr	z,null		; .. skip it
	ld	hl,nargs	; Init pointer
	cp	(hl)		; Compare number of args
	jr	z,.arg		; .. max
	jr	nc,null		; .. too many
.arg:
	ld	c,a		; Save argument # searched for
	ld	hl,argbuf	; Init pointer
	xor	a		; .. and end character
gtarg0:
	dec	c
	jr	z,gtarg2	; Test found
gtarg1:
	cp	(hl)		; Skip item if not found
	inc	hl
	jr	nz,gtarg1
	jr	gtarg0		; Retry
null:
	ld	hl,nulbuf	; Set dummy return
gtarg2:
	pop	bc
	ret

	dseg

nulbuf:
	db	endstr

	end