;;;;;;; Fast Text-to-Unix Conversion (ftuc.asm) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; Started:	21-Dec-2000
;; Updated:	22-Dec-2000
;;
;; Copyright 2000 G. Adam Stanislav.
;; All rights reserved.
;;
;;;;;;; v.1 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
%include	'system.inc'

section	.data
	db	'Copyright 2000 G. Adam Stanislav.', 0Ah
	db	'All rights reserved.', 0Ah
usg	db	'Usage: ftuc filename', 0Ah
usglen	equ	usg
co	db	"ftuc: Can't open file.", 0Ah
colen	equ	co
fae	db	'ftuc: File access error.', 0Ah
faelen	equ	fae
ftl	db	'ftuc: File too long, use regular tuc instead.', 0Ah
ftllen	equ	ftl
mae	db	'ftuc: Memory allocation error.', 0Ah
maelen	equ	mae

section	.text

align 4
memerr:
	push	dword maelen
	push	dword mae
	jmp	short error

align 4
toolong:
	push	dword ftllen
	push	dword ftl
	jmp	short error

align 4
facerr:
	push	dword faelen
	push	dword fae
	jmp	short error

align 4
cantopen:
	push	dword colen
	push	dword co
	jmp	short error

align 4
usage:
	push	dword usglen
	push	dword usg

error:
	push	dword stderr
	sys.write

	push	dword 1
	sys.exit

align 4
global	_start
_start:
	pop	eax		; argc
	pop	eax		; program name
	pop	ecx		; file to convert
	jecxz	usage

	pop	eax
	or	eax, eax	; Too many arguments?
	jne	usage

	; Open the file
	push	dword O_RDWR
	push	ecx
	sys.open
	jc	cantopen

	mov	ebp, eax	; Save fd

	sub	esp, byte stat_size
	mov	ebx, esp

	; Find file size
	push	ebx
	push	ebp		; fd
	sys.fstat
	jc	facerr

	mov	edx, [ebx + st_size + 4]

	; File is too long if EDX != 0 ...
	or	edx, edx
	jne	near toolong
	mov	ecx, [ebx + st_size]
	; ... or if it is above 2 GB
	or	ecx, ecx
	js	near toolong

	; Do nothing if the file is 0 bytes in size
	jecxz	.quit

	; Map the entire file in memory
	push	edx
	push	edx		; starting at offset 0
	push	edx		; pad
	push	ebp		; fd
	push	dword MAP_SHARED
	push	dword PROT_READ | PROT_WRITE
	push	ecx		; entire file size
	push	edx		; let system decide on the address
	sys.mmap
	jc	near memerr

	mov	edi, eax
	mov	esi, eax
	push	ecx		; for SYS_munmap
	push	edi

	; Use EBX for state machine
	mov	ebx, ordinary
	mov	ah, 0Ah
	cld

.loop:
	lodsb
	call	ebx
	loop	.loop

	cmp	ebx, ordinary
	je	.filesize

	; Output final lf
	mov	al, ah
	stosb
	inc	edx

.filesize:
	; truncate file to new size
	push	dword 0		; high dword
	push	edx		; low dword
	push	eax		; pad
	push	ebp
	sys.ftruncate

	; close it (ebp still pushed)
	sys.close

	add	esp, byte 16
	sys.munmap

.quit:
	push	dword 0
	sys.exit

align 4
ordinary:
	cmp	al, 0Dh
	je	.cr

	cmp	al, ah
	je	.lf

	stosb
	inc	edx
	ret

align 4
.cr:
	mov	ebx, cr
	ret

align 4
.lf:
	mov	ebx, lf
	ret

align 4
cr:
	cmp	al, 0Dh
	je	.cr

	cmp	al, ah
	je	.lf

	xchg	al, ah
	stosb
	inc	edx

	xchg	al, ah
	; fall through

.lf:
	stosb
	inc	edx
	mov	ebx, ordinary
	ret

align 4
.cr:
	mov	al, ah
	stosb
	inc	edx
	ret

align 4
lf:
	cmp	al, ah
	je	.lf

	cmp	al, 0Dh
	je	.cr

	xchg	al, ah
	stosb
	inc	edx

	xchg	al, ah
	stosb
	inc	edx
	mov	ebx, ordinary
	ret

align 4
.cr:
	mov	ebx, ordinary
	mov	al, ah
	; fall through

.lf:
	stosb
	inc	edx
	ret