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Hi,

call me an idiot, but I have no idea how to manage this problem. It's easy, don't worry.
I just want to access a string and put something in there - let's say "AB":


.data
szTemp		db	260 DUP(0)

.code
;...
		invoke	ChangeString, OFFSET szTemp

ChangeString 	proc		buffer:DWORD
		mov		dl, 65
		mov		dh, 66
		mov		byte ptr ,dl
		inc 	buffer
		mov		byte ptr ,dh
ChangeString	endp

It doesn't work out, though. How can I do this?

Thanks,
Claus

Posted on 2006-10-21 05:21:32 by Claus von der Burchard

Re: Accessing a string

Hi Claus,

Just load a register with the buffer address, let's say Esi:

Push Esi
Mov Esi,buffer
Mov Byte Ptr , Dl
Inc Esi
Mov Byte Ptr , Dh
Pop Esi

Regards,

Ramon

Posted on 2006-10-21 05:33:29 by rsala

Re: Accessing a string

Loading a string? Just copy the bytes. ;)

Posted on 2006-10-21 05:37:55 by roticv

Re: Accessing a string


ChangeString 	proc		buffer:DWORD
  mov eax, 
  mov byte ptr , 'H'
  mov byte ptr , 'i',
  mov byte ptr , ' '
  mov byte ptr , 'W'
  mov byte ptr , 'o'
  mov byte ptr , 'r'
  mov byte ptr , 'l'
  mov byte ptr , 'd'
  mov byte ptr , 0
  ret
ChangeString	endp

Pretty bad since it does't contain a buffer-length parm and can thus be overflowed, but... well :)

Posted on 2006-10-21 08:19:16 by f0dder

Re: Accessing a string

Alright,

thanks alot.

I was just writing a small function that converts a number to a string:

ConvertNumberToString proc		buffer:DWORD, number:DWORD
		mov		eax, number
		
		push	esi
		mov		esi, 
		
		mov		ebx, 10
		xor		ecx, ecx
numberloop:		
		xor		edx, edx
		push	ecx
		div		ebx
		add		edx, 48
		pop		ecx
		push	edx
		inc		ecx
		cmp		eax, 0
		je		writestring
		jmp		numberloop

writestring:
		pop		edx
		mov		byte ptr , dl
		inc		esi
		dec		ecx
		jnz		writestring
		
		mov		byte ptr , 0
		pop		esi
		ret
ConvertNumberToString endp

I know, it's not optimized yet, but it works out for me.

Claus

PS: The string class looks interesting, but it would surely be an overkill for this function.

Posted on 2006-10-22 09:27:16 by Claus von der Burchard

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