title	'ERQ - Selective file erase'

CR	EQU	13
LF	EQU	10
ESC	EQU	27
TFCB	EQU	5CH

	org	100h

erq:	mov	dx,TFCB
	mov	cl,17	;Search first
	CALL	BDOS
	cmp	al,255
	jnz	FILFND
	mov	dx,offset NFMSG
	call	OUTBUF
	mov	cl,0
	jmp	BDOS
OUTBUF:	mov	cl,9	;Print string
	jmp	BDOS
FILFND:	mov	bx,offset NAMBUF
	PUSH	bx
NXTFIL:
	mov	cl,5
	shl	al,cl
	add	al,81h
	mov	ah,0
	mov	si,ax
	POP	di
	mov	cx,11
	rep movs al,al
	PUSH	di
	mov	cl,18	;Search next
	mov	dx,tfcb
	CALL	BDOS
	cmp	al,255
	jnz	NXTFIL
	POP	bx
	mov	byte ptr [bx],80H	;End of list indicator
	mov	bx,offset NAMBUF
DELCHK:	mov	NBPOS,bx
				;Output name
	mov	cx,8
NXTCR2: mov	al,[bx]
	AND	al,7FH
	cmp	al,' '
	jz	ENDNAM	;End of name
	PUSH	bx
	PUSH	cx
	CALL	CONOUT
	POP	cx
	POP	bx
	INC	bx
	loop	NXTCR2
ENDNAM:	mov	ch,0
	ADD	bx,cx
	PUSH	bx
	mov	al,[bx]
	AND	al,7FH
	cmp	al,' '
	jz	ENDTYP	;No filetype
	mov	al,'.'
	CALL	CONOUT
				;Output type
	mov	cx,3
	POP	bx
	PUSH	bx
NXTCR3: mov	al,[bx]
	AND	al,7FH
	cmp	al,' '
	jz	ENDTYP	;End of type
	PUSH	bx
	PUSH	cx
	CALL	CONOUT
	POP	cx
	POP	bx
	INC	bx
	loop	NXTCR3
ENDTYP: mov	dx,offset DFMSG1	;Output rest of the message
	CALL	OUTBUF
	POP	bx
	test	byte ptr [bx],80h
	jz	NOTR_O	;Check for file R/O
	mov	dx,offset DFMSG2
	CALL	OUTBUF
NOTR_O: mov	dx,offset DFMSG3
	CALL	OUTBUF
	mov	cl,1	;Console input
	CALL	BDOS
	cmp	al,ESC
	jnz	$+3
	RET
	AND	al,5FH	;Convert lowercase to uppercase
	cmp	al,'Y'
	jnz	NXTCHK
	mov	si,NBPOS
	mov	di,TFCB+1
	mov	cx,11
	rep movs al,al
	mov	bx,TFCB+9
	test	byte ptr [bx],80h
	jz	NTR_O
	and	byte ptr [bx],7fh
	mov	dx,TFCB
	mov	cl,30	;Set file attributes
	CALL	BDOS
NTR_O:	mov	dx,TFCB
	mov	cl,19	;Delete file
	CALL	BDOS
NXTCHK:	mov	al,CR
	CALL	CONOUT
	mov	al,LF
	CALL	CONOUT
	mov	bx,NBPOS
	add	bx,11
	test	byte ptr [bx],80h
	mov	cl,0
	jnz	bdos
	jmp	DELCHK

CONOUT: mov	dl,al
	mov	cl,2	;Console output
BDOS:
	push	es
	int	224
	pop	es
	ret

NFMSG	db	'File(s) not found$'
DFMSG1	db	' exists$'
DFMSG2	db	' and is R/O$'
DFMSG3	db	'.  Do you want it deleted?$'

NBPOS	dw	0
NAMBUF	rs	11*64
	db	0

	END