Line Incrementation Problem using a86

[welsh_spoon]

I'm trying to write some code that reads a file, copies and prints to a seperate file, with line numbering, ive got quite far, just dont know how to do the line numbering, if anyone could help me with it, it would be superb, thank you!

Here's my code:
JMP Start
cr equ 13h
lf equ 10h
msg1 db 'Cannot Open File, Aborting Program...',cr,lf,'$'
msg2 db 'Cannot Open Output File, Aborting Program...',cr,lf,'$'
msg3 db 'Cannot Write Data to File, Aborting Program...',cr,lf,'$'
msg4 db 'Cannot Reading from File, Aborting Program...',cr,lf,'$'
FileName db 'original.txt',0
OutputFile db 'Output.txt',0
FileHandle1 dw ?
FileHandle2 dw ?
Buffer db ?
Position dw 0

Start:
mov ah,3dh
mov al,0
lea dx,FileName
int 21h
jnc GoodOpen
lea dx,msg1
mov ah,9
int 21h
jmp PgmExit
GoodOpen:
mov FileHandle1,ax
mov ah,3ch
mov cx,0
lea dx,OutputFile
int 21h
jnc GoodOpen2
lea dx,msg2
mov ah,9
int 21h
mov ah,3eh
mov bx,FileHandle1
int 21h
jmp PgmExit
GoodOpen2:
mov FileHandle2, ax
ReadFileLP:
mov bx,FileHandle1
mov cx,1
lea dx,Buffer
mov ah,3Fh
int 21h
jc BadRead
cmp ax,1
jz ReadOK
jmp AtEOF
ReadOK:
mov al,Buffer
cmp al,cr
jb NotLower
cmp al,lf
ja LineNo
mov al, 5fh
NotLower:
mov Buffer,al
mov bx,FileHandle2
mov cx,1
lea dx,buffer
mov ah,40h
int 21h
jc BadWrite
cmp ax,1
jz ReadFileLP
LineNo:
;here is the line number stuff
BadWrite:
lea dx,msg3
mov ah,9
int 21h
jmp AtEOF
BadRead:
lea dx,msg4
mov ah,9
int 21h
AtEOF:
mov bx,FileHandle1
mov ah,3eh
int 21h
mov bx,FileHandle2
mov ah,3eh
int 21h
PgmExit:
mov ah,4ch
int 21h

[Aedan]

Nothing like a few comments is there?

[Gizmo]

I'm going to have to peel out my old DOS books when I get home. I haven't done much low-level DOS style access in quite a while. Everything I do these days uses DeviceIoctl.

[Kaitain]

Glad to see Intel have moved on so far since the 8051

[Allan]

Why don't you put the messages and variables in the .DATA segment instead of the .CODE segment? Then you wouldn't need a JMP Start command.

As mentioned you really should use comments more, it took me a while to read through your program. Some line breaks before every label would be good too.

My initial solution to your problem would be to make an array, put the line number in the first array position, then a space, and then add the line.

Line number itself could just be a variable (a DW is probably enough) that you increment (INC) after every insertion.

Sorry, I haven't messed with file handling in assembly so thats the best I can think of right now.

[Kaitain]

Not sure how files are handled in x86 processors. In the 8051 it would be copied byte by byte from one location to the next. Line counting would be pretty simple then

.DSEG
.EQU lineno,somewhere ; where somewhere is a memory location suitable for the job

.CSEG
; in file handling code
CJNE buffer,cr,noline ; skips the next line if not a carriage return
CALL linecount
noline: Rest of file handling code

linecount: <move the cr and lf bytes to the output file>
inc lineno ; if you're likely to have more lines than you can address, then
; you might do better with ADDC and check for overflow with JC
MOV filehandle1,lineno
RET


This was all written after an evening in the pub, so is also completely untested

[danrok]

Why does this program always result in a crash?

If glass is empty then
goto bar
repeat until time = '23:30'

[Kaitain]

Originally Posted by danrok

Why does this program always result in a crash?

If glass is empty then
goto bar
repeat until time = '23:30'

Well if you will try to put BASIC into an assembler compiler (Or alternatively, if you will try to have a decent night on the booze under British laws )