"almas" <almes@[EMAIL PROTECTED]
> wrote in message
news:47eebff8$0$857$ba4acef3@[EMAIL PROTECTED]
> Hi every body.
> I have a text.... many lines, end of line is OD OA
> I want to change the beginig of each line
> the first 5 bytes remplaced by "¿"
>
> Below my code... sorry it is not OK
> Who have an idea ?
>
> I use DOS Operating System compiler is A86
>
1) replace ("remplace") engine
2) add safety and terminating buffer "term:" after "bytes:"
> mov si,0080h
> lodsb
> cbw ;extend AL to AX
> xchg bx,ax ;swap size to bx for indexing
> mov byte [bx+si],0 ;null terminate command line
> mov di,inbuff ;our buffer
> ; dospc: cmp byte [si],32 ;any leading spaces ? ; jne nospc ;nooo
> inc si ;yeahh, dump it ; jmp dospc ;check next
> nospc: mov cx,1 ;we're here, so we got one arg
> copy1: lodsb ;load byte SI to AL
> cmp al,0 ;0 ?(end of line)
> je done ;yeahh
> stosb ;noo, move AL to DI, incrase DI
> jmp short copy1 ;go on
> done: mov byte [di],0 ;null terminate END of PARSE
> gotfile:
> mov ax,3d12h ; open file READ/WRITE/NO SHARE
> mov dx,offset inbuff ;filename
> int 21h
>
> fopok: xchg ax,bx
> ; ; handle ; mov word [bytes],256 ; buffer size
> ; ; NOTE BX will not change I put value 0 into count 1 and 2
> ; ; xor ax,ax ; mov offset count1,ax ; clear out ; mov offset count2,ax
>
> readlop: mov ah,3fh ; read file ; mov bx,[filehandle]
> mov cx,[bytes] ;read buffer full
> mov dx,offset address ;buffer
> int 21h
> cmp ax,0 ;nothing read ? (end of file)
> ja main ;nooo, do the work
> jmp short quit ;yeahh, we're done
> main:
> mov [bytes],ax ;bytes read
> mov cx,ax ;counter
> mov si,address ;file buffer
> ; ---------- here the "engine" --------------
; replace i.e., "remplace" engine ;-)
mov di,si
add si,cx
push bx ; save the handle
push cx
cld
mloop: ; is it end of line ?
mov al,0Dh
repne scasb
mov al,0Ah
scasb
jnz mloop
push di ; blank line ? Yes, skip.
mov al,0Dh
scasb
pop di
jz mloop
cmp di,si ;term ; past end of buffer ? Yes, exit.
ja oloop
mov cx,5 ; i want to remplace 5 bytes by ¨
mov al,0A8h
rep stosb
cmp di,si ;term ; past end of buffer ? Yes, exit.
ja oloop
jmp mloop
oloop:
pop cx
sub cx,di ; resize file buffer
add cx,address
pop bx ; restore handle
> ; ----------- end of my "engine " -----------
>
> mov ax,4200h ; seek set file position beginning
> mov cx,[count1] ;most significant part of offset
> mov dx,[offset count2] ;least significant part of offset
> int 21h
>
> mov cx,[bytes] ;get offset size
> mov dx,[offset count1] ;the most significant part
> mov ax,[count2] ;the least significant part
> add ax,cx ;add offset to least sig part
> adc dx,0 ;add with carry
> mov [offset count1],dx ;save them back for next loop
> mov [count2],ax
>
> mov ah,40h ; write to file mov bx,[filehandle]
> mov dx,offset address ;buffer
> int 21h
> cmp word [bytes],256 ;less than 256 bytes left ?
> jb quit ;yeahh, must be last read
> jmp short readlop ;noo, go on reading
> quit: ; cmp word [filehandle],0 ;any filehandle
>
> mov ah,3eh ; close file
> int 21h
> nofile: ret ; int 20h
>
> ; DATA
> bytes dw ,100h ; size buffer for file
term: db 0dh,0ah,0,0,0,0,0
> filesize: db: 0,0
> filehandle dw 0,0
> count1 dw 0,0 ; at the begining, value must be 0
> count2 dw 0,0
> inbuff: db: 0,0
> address: db: ,0,0
I know there is at least one bug in "engine" but it is trivial... Also,
I'm
not sure if the cx calculation is correct for the rest of your code.
Rod Pemberton
|
