Print Page - jump over 2 zeros in al

Title: jump over 2 zeros in al
Post by: ragdog on January 31, 2008, 09:03:55 PM

hi ::)

i have problem with read my hex string.

It print not the 2 string! I have yet 2x Inc
esi write to jump over the 2 zero´s or not?

example to print: msgbox Test1
msgbox Test2
msgbox Test3

Code Select


.data
sztest       db054h,065h,073h,074h,031h,000h,000h,054h,065h,073h,074h,032h,000h,000h,054h,065h,073h,074h,033h,00h,00h
;Test100Test200Test300


.code

readstrings proc

LOCAL szDest1[256]:BYTE
LOCAL szDest2[256]:BYTE
LOCAL szDest3[256]:BYTE
LOCAL szDest4[256]:BYTE
LOCAL szDest5[256]:BYTE

            xor esi,esi
            xor edi,edi
	        mov esi,offset sztest       
@Read_Test1:
	        mov al, byte ptr [esi]	     
            mov byte ptr szDest1[edi], al 
            inc edi                      ;inc dest buffer
            inc esi                      ;inc src buffer
            cmp al,00h                   ;compare if al 00h
            jnz @Read_Test1              ;jmp if al not 00h
         invoke MessageBox,hWnd,addr szDest1,0,MB_OK
            
            inc esi
            inc esi
@Read_Test2:
	        mov al, byte ptr [esi]	     
            mov byte ptr szDest2[edi], al 
            inc edi                      ;inc dest buffer
            inc esi                      ;inc src buffer
            cmp al,00h                   ;compare if al 00h
            jnz @Read_Test2              ;jmp if al not 00h
         invoke MessageBox,hWnd,addr szDest2,0,MB_OK
...
..
.

readstrings endp

thanks in forward
ragdog

Title: Re: jump over 2 zeros in al
Post by: RuiLoureiro on January 31, 2008, 09:17:30 PM

Quote from: ragdog on January 31, 2008, 09:03:55 PM

@Read_Test1:
mov al, byte ptr [esi]
mov byte ptr szDest1[edi], al
inc edi ;inc dest buffer
inc esi ; points to the next 0
cmp al,00h ;compare if al 00h
jnz @Read_Test1 ;jmp if al not 00h
invoke MessageBox,hWnd,addr szDest1,0,MB_OK

inc esi
; inc esi

Hi,
I think you have 2 inc esi instead of inc esi. Is it ?
Rui

Title: Re: jump over 2 zeros in al
Post by: ragdog on January 31, 2008, 09:31:47 PM

i removed a one "inc esi"
No, unfortunately, is the same problem!

Thank you

Title: Re: jump over 2 zeros in al
Post by: RuiLoureiro on January 31, 2008, 09:51:11 PM

lea edi, szDest1
and lea edi, szDest2 to get the address of szDest1 ... ? Doesnt work ?

Title: Re: jump over 2 zeros in al
Post by: ragdog on January 31, 2008, 09:59:11 PM

It is any other problem, the first string is displayed to the msgbox not the string 2 ...

:'(

Title: Re: jump over 2 zeros in al
Post by: MichaelW on January 31, 2008, 10:03:19 PM

The main problem is that you are not setting edi back to zero before the second loop. Also, you need only one inc esi because the first loop is leaving esi set to the second null.

Title: Re: jump over 2 zeros in al
Post by: ragdog on January 31, 2008, 10:08:54 PM

i have it inc esi
xor edi,edi

thanks michael

ragdog

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