Help with file I/O

[Elfman32]

HI all.

what im trying to do is create a file (lets call is CFile) then open and read another file (RFile) and write the data to the CFile here's what i have so far :

.model small
.stack 100h

.data


;//*******************************************************************************//
;//*************************Buffers / arrays ************************************//
BUFFER DW 10 DUP (?) ;Buffer - data from the read file will be saved here
;Before being written to teh created file
FHDL DW ? ;A file handle
offsetbuffer DW 10 DUP (?) ; ????????????????
FHandle DW ?
Rhandle dw ?
Chandle dw ?
;//******************************************************************************//

;//**************************Error messages***********************************//
FNF DB 13, 10,'File Not Found', 13, 10,'$'
TMF DB 13, 10,'Too Many Files open', 13, 10,'$'
AD DB 13, 10,'Access Denied', 13, 10,'$'
IA DB 13, 10,'Invalid Access', 13, 10,'$'
RE DB 13, 10,'Read Error', 13, 10,'$'
EOF DB 13, 10,'End of File', 13, 10,'$'
;//***************************************************************************//

;//***************************File paths******************************//
CFile db 'c:\Cmprssd.txt', 0 ;File to be created
RFile DB 'sample.txt',0 ; Filename in quotes, 0 = eof char
;//*******************************************************************//


.code

BeginHere:
mov ax, @data ;set data segment
mov ds, ax

;Create and open CFile

mov ah, 3ch
mov cx, 0
mov dx, offset CFile
int 21h

jc error
mov Chandle, ax

error:
nop

;//***********************open file for reading ***************//
mov ah, 03dh ;Open file dos function
mov al, 0 ;Sets up file as read only
mov dx, offset RFile ;Filename (above) to DX
int 21h ;interupt for dos function

jc ErrorHandler ; Go to errorhandler
mov Rhandle, ax

;//*************************************************************//




;//***********************open file for writing ***************//
mov ah, 03dh ;Open file dos function
mov al, 2 ;Sets up file as read only
mov dx, offset CFile ;Filename (above) to DX
int 21h ;interupt for dos function

jc ErrorHandler ; Go to errorhandler
mov Chandle, ax

;//*************************************************************//


;//*************************************************************//
;//******** loop to read from RFile adn write to CFile ********//


LP: ; Start a segment of code to be looped
; In this case looped reading of data
; Into a buffer from a file


mov ah, 03fh ; read data
mov dx, offset buffer
mov cx, 6 ; Set number of char to be read
mov bx, Rhandle
int 21h ; Dos interupt to allow dos function to run

jc ReadError

cmp ax, cx
jne Eofile
mov si, 0


Prt_LP :

;//Write to file//
mov bx, Chandle
mov dx, buffer[si]
mov ah, 40h

mov cx, 5
int 21h
;//*************//

inc si
cmp ax, cx
jne Eofile
mov si, 0

;loop Prt_LP ;go back to next read
;jmp LP


ErrorHandler:
cmp ax, 2
jz NotFound
cmp ax, 4
jz TooMany
cmp ax, 5
jz Denied
cmp ax, 12
jz Invalid
jmp ExitProg


NotFound:
mov dx, offset FNF
mov ah, 09h
int 21h
jmp ExitProg
TooMany:
mov dx, offset TMF
mov ah, 09h
int 21h
jmp ExitProg
Denied:
mov dx, offset AD
mov ah, 09h
int 21h
jmp ExitProg
Invalid:
mov dx, offset IA
mov ah, 09h
int 21h
jmp ExitProg




Eofile:
mov cx, ax
jcxz Eof2
mov si, 0

Finish:
mov dx, buffer[si]
mov ah, 02h
int 21h
inc si
loop Finish


Eof2:
mov bx, FHDL
mov ah, 03ch
int 21h
jc Close_error

ReadError:
mov dx, offset RE
mov ah, 09h
int 21h
jmp ExitProg

Close_error:
;Do something here
;To deal with possible
;Closing errors
jmp ExitProg;


ExitProg:
mov ah, 04ch
int 21h
End BeginHere


any idea why it's not working.

It wont even create the file thanks in advance.

 

[strettonman]

At a quick glance I can't see any files being closed, which is not an optional extra if you want stuff flushed to disk.