Hello everybody

I"m trying to figure out how to add Trailing backslash ("\" at the of string,I"m not too good in assembler

I looked into ascii table,and backslash is "92" as byte.

I tried to load that string into esi and then Add that byte,but it aways adds at beginning of that string.

ESI: "C:"
ADD BYTE PTR DS:[ESI],92

Can please somebody help me ?

EDIT: I need to detect length of that string in ESI ? if yes please how.

assuming you know where the original string is and can transfer it to edi this should do it



01013D79 B8 5C000000 MOV EAX,5C
01013D7E BF 705D0101 MOV EDI,calc.01015D70 ; ASCII "c:"
01013D83 47 INC EDI
01013D84 47 INC EDI
01013D85 AA STOS BYTE PTR ES:[EDI]
01013D86 90 NOP




before
[CODE]
01015D70 63 3A 00 c:.

after
01015D70 63 3A 5C c:\

[CODE]

add doesnt add strings it is a mathematical operator
it can do your work provided the original byte there was 0x00 if it was anything else it will add 92 to original contents

stosb == store byte at position
inc is to get to the place

you should use lstrcat() function instead of this jugglery

Thank you ,but if that string is dynamically changed at runtime ? how I can obtain length of that string ?

Can you please example of lstrcat ? please.

or Like That:
push esi
push eax
CALL DWORD PTR DS:[73421088]

Hi,
"lots" of examples below
http://www.asmcommunity.net/board/?topic=330.0

Oh Thank you so much .. I appreciated that