title	miscellaneous
	include	asm.inc

	public	abort_if_cf
;	public	move_file_pointer
;	public	read_from_file
	public	strcmpi

	.data
	extw	psp

	.const
ertx_aborting	db	'Aborting',0
;ertx_disk_full	db	'Disk full',0

	.data?
argc		dw	?
argv		dd	?


	.code
 extn get_strerror,set_strerror,perror
 extn ms_dos_strerror,malloc


;;	abort_if_cf
;
abort_if_cf proc
	jnc	aic2
	call	get_strerror
	jz	aic1
	movx	si,NULL_POINTER
	call	perror
aic1:	lea	ax,ertx_aborting
	call	set_strerror
	call	perror
	call	exit_with_error
aic2:	ret
abort_if_cf endp


;;	close file
;
;	entry	BX	handle
;	exit	Cf	0
;	uses	AX
;
close_file proc
	mov	ah,3Eh
	jmp	ms_dos_strerror
close_file endp


;;	err disk full
;
;	exit	Cf	1
;	uses	AX
;
;err_disk_full proc
;	lea	ax,ertx_disk_full
;	jmp	set_strerror
;err_disk_full endp


;;	exit program
;
exit_program proc
	mov	ax,4C00h
	jmp	ms_dos
exit_program endp


;;	exit with error
;
exit_with_error proc
	mov	ax,4C01h
	jmp	ms_dos
exit_with_error endp


;;	get vector
;
;	entry	AL	vector #
;	exit	DS:SI	selected vector
;		Zf	if null vector
;	uses	AX
;
get_vector proc
	mov	ah,0
	add	ax,ax
	add	ax,ax
	xchg	ax,si
	xor	ax,ax
	mov	ds,ax
	lds	si,[si]
	mov	ax,ds
	or	ax,si
	ret
get_vector endp


;;	input file size
;
;	entry	BX	file handle
;	exit	DX AX	size
;
input_file_size proc
	pushm	cx,di,si
	mov	ax,4201h		; get current position
	movx	cx,0
	movx	dx,0
	call	ms_dos_strerror
	jc	ifs1
	mov	si,dx			;  into SI DI
	mov	di,ax

	mov	ax,4202h		; move to end of file
	movx	dx,0
	call	ms_dos_strerror
	jc	ifs1

	pushm	ax,dx
	mov	ax,4200h		; restore file position
	mov	cx,si
	mov	dx,di
	call	ms_dos_strerror
	popm	dx,ax

ifs1:	popm	si,di,cx
	ret
input_file_size endp


;;	move file pointer
;
;	entry	BX	file handle
;		DX AX	file position
;	exit	Cf	if error
;	uses	AX
;
;move_file_pointer proc
;	push	cx
;	mov	cx,dx
;	mov	dx,ax
;	mov	ax,4200h
;	call	ms_dos_dialog
;	pop	cx
;	ret
;move_file_pointer endp


;;	ms dos
;
ms_dos	proc
	int	21h
	ret
ms_dos	endp


;;	open input file
;
;	entry	DS:SI	string
;	exit	AX,BX	handle
;		Cf	if error, error text set
;	calls	offset_dos_error, ms_dos
;
open_input_file proc
	mov	ax,3D00h		; (use 3D20 for shared access read)
	xchg	dx,si
	call	ms_dos_strerror
	xchg	dx,si
	mov	bx,ax
	ret
open_input_file endp


;;	read command line
;
;	exit	DS:SI	program command line
;
read_command_line proc
	mov	ds,psp[bp]
	mov	si,81h
	ret
read_command_line endp


;;	read environment
;
;	exit	DS:SI	environment
;
read_environment proc
	xor	si,si
	mov	ds,psp[bp]
	mov	ds,[si+2Ch]
	ret
read_environment endp


;;	read from file
;
;	entry	BX	file handle
;		CX	byte count
;		ES:DI	destination
;	exit	AX	number of bytes read
;		Cf	if error
;
;read_from_file proc
;	push	ds
;	mov	ah,3Fh
;	push	es
;	pop	ds
;	xchg	dx,di
;	call	ms_dos_dialog
;	xchg	di,dx
;	pop	ds
;	ret
;read_from_file endp


;;	remove
;
;	entry	DS:SI	filename to delete
;	exit	Cf	if error
;	uses	AX
;
remove	proc
	mov	ah,41h			; delete file
	xchg	dx,si
	call	ms_dos_strerror
	xchg	dx,si
	ret
remove	endp

	even
;;	restore most
;
;	note	never call this routine
;
restore_most proc
	popm	bp,es,ds,si,di,dx,cx,bx
	ret
restore_most endp

	even
;;	save most
;
;	note	saves all registers except AX and BP.  however, the current
;		version also saves BP because the code works out that way.
;		the registers are automatically restored.  this routine is
;		called with a return address as the top of stack.
;
save_most proc				; +16 inner ret adr, +18 outer ret adr
	push	cx			; +14
	push	dx			; +12
	push	di			; +10
	push	si			; +8
	push	ds			; +6
	push	es			; +4
	push	bp			; +2
	lea	bp,restore_most		;     after execution of inner
	push	bp			; +0  routine, return to restore_most
	mov	bp,sp
	xchg	bx,[bp+16]		;	bx above cx
	push	bx			; -2	setup return to inner routine
	mov	bx,[bp+16]		;	restore original BX and BP
	mov	bp,[bp+2]
	ret
save_most endp


;;	set argc argv
;
;	exit	Cf	if no memory
;	uses	AX,CX,DI,SI,ES,DS
;
set_argc_argv proc
	mov	cx,256
	call	malloc
	jc	saa9			; if no memory

	mov	argc[bp],1
	mov	wptr argv[bp],di
	mov	wptr argv[bp+2],es

	mov	ah,30h
	call	ms_dos
	cmp	al,3
	jb	saa10			;  if prior to DOS version 3.x

	call	read_environment	; skip environment
saa1:	call	strskp
	lodsb
	cmp	al,NULL_CHAR
	jne	saa1
	lodsw				;  (skip 1)

	call	strcpy			; copy program name which appears
	inc	di			;  after environment

saa2:	call	read_command_line
saa3:	call	strskp_white
	cmp	al,CR_CHAR
	je	saa7			; if no more arguments

	inc	argc[bp]
	jmp	saa5
saa4:	stosb
saa5:	lodsb
	cmp	al,SPACE_CHAR
	jbe	saa6
	cmp	al,','
	je	saa6
	cmp	al,'~'
	jbe	saa4

saa6:	cmp	al,CR_CHAR
	mov	al,NULL_CHAR
	stosb
	jne	saa3

saa7:	inc	di			; word align table
	and	di,-2

	lds	si,argv[bp]		; get ptr to first argument
	mov	wptr argv[bp],di	; set pointer list offset
	mov	cx,argc[bp]		; get list count (cannot==0)

saa8:	mov	ax,si			; build pointer list
	stosw
	call	strskp
	loop	saa8
	clc
saa9:	ret

saa10:	mov	ax,'C'
	stosw
	jmp	saa2
set_argc_argv endp


;;	stosb tmp path
;
;	entry	ES:DI	destination
;	exit	DI	updated
;	uses	AX
;
stosb_tmp_path proc
	mov	al,NULL_CHAR
	stosb
	dec	di
	ret
stosb_tmp_path endp


;;	strcmpi
;
;	entry	DS:SI	string1
;		ES:DI	string2
;	exit	Zf	if string1==string2
;	uses	AX
;
strcmpi proc
	pushm	di,si
sci1:	mov	ah,es:[di]
	lodsb
	or	ax,ax
	jz	sci2			;  if same strings
	inc	di
	call	tolower
	xchg	al,ah
	call	tolower
	cmp	ah,al
	je	sci1			;  if strings match so far
sci2:	popm	si,di
	ret
strcmpi endp


;;	strcpy
;
;	entry	DS:SI	source ptr
;		ES:DI	destination ptr
;	exit	SI	updated past NULL
;		DI	updated, points to NULL
;	uses	AX
;
strcpy	proc
	lodsb
	stosb
	cmp	al,NULL_CHAR
	jne	strcpy
	dec	di
	ret
strcpy	endp


;;	strcpy limit
;
;	entry	DS:SI	source pointer
;		ES:DI	destination pointer
;		DX	destination limit
;	exit	DI	updated to last character in destination
;	uses	AX
;
strcpy_limit proc
	push	si
scl1:	cmp	di,dx
	jae	scl2			; if at destination limit

	lodsb				; else copy one character
	stosb
	cmp	al,0
	jne	scl1

	dec	di
scl2:	pop	si
	ret
strcpy_limit endp


;;	strlen
;
;	entry	DS:SI	string
;	exit	CX	byte count excluding NULL
;	uses	AX
;
strlen	proc
	mov	cx,si
sln1:	lodsb
	cmp	al,NULL_CHAR
	jne	sln1
	xchg	cx,si
	sub	cx,si
	dec	cx
	ret
strlen	endp


;;	strskp
;
;	entry	DS:SI	asciiz string ptr
;	exit	SI	updated past null
;	uses	AX
;
strskp	proc
	lodsb
	cmp	al,NULL_CHAR
	jne	strskp
	ret
strskp	endp


;;	strskp white
;
;	entry	DS:SI	text ptr
;	exit	SI	updated past spaces and tabs
;		AL	non-white character
;
strskp_white proc
	lodsb
	cmp	al,SPACE_CHAR
	je	strskp_white
	cmp	al,TAB_CHAR
	je	strskp_white
	dec	si
	ret
strskp_white endp


;;	tolower
;
;	entry	AL	char
;	exit	AL	lower cased AL
;
tolower proc
	cmp	al,'A'
	jb	tol1
	cmp	al,'Z'
	ja	tol1
	or	al,20h
tol1:	ret
tolower endp


	public	ms_dos,read_command_line,read_environment,set_argc_argv,strcpy
	public	argv,argc,exit_program,exit_with_error,get_vector,tolower
	public	close_file,open_input_file,input_file_size
	public	remove,save_most,strlen,strcpy_limit,strskp

	end