;///////asci to integer proc aka atoi()
;///////Coded by fakedminded/berniee (2008)
;///////ass-koder.de.vu ||fakedminded.wordpress.com
;///////Details: This manage to get char (decimal) into integer through several loops!
;///////         NOT OPTIMIZED!

;|---------___________________________________________----------------|
;|                                                                    |
;|                     assembeler atoi()                              |
;|                                                                    |
;|--------___________________________________________-----------------|


.586
.model flat,stdcall
option casemap:none

include \masm32\include\windows.inc
include \masm32\include\user32.inc
include \masm32\include\kernel32.inc

includelib \masm32\lib\kernel32.lib
includelib \masm32\lib\user32.lib


.data
string1 db "5567112",0

.code
atoi:
mov ebp,esp
push esi
invoke lstrlen,esi
pop esi
mov ecx,eax
add esi,eax
xor edx,edx
xor eax,eax
dec esi

@@:

push ecx  ;loop counter
push edx  ;digit counter
push eax  ;result--addition
call seek_order
xor eax,eax
mov al,byte ptr[esi]
sub al,30h
cmp al,0
jb err
xor edx,edx
mul ecx
xchg ecx,eax
pop eax
add eax,ecx
pop edx
pop ecx
inc edx
dec esi

loop @b
mov esp,ebp
ret
err:
xor eax,eax
dec eax
mov esp,ebp
ret

seek_order:
or edx,edx
jz exit_sk
mov ecx,edx
mov edx,1

@@:
push ecx

push edx
xor ecx,ecx
mov ecx,edx
xor edx,edx
mov eax,10

mul ecx
pop edx
mov edx,eax

pop ecx
loop @b

xchg ecx,eax
ret

exit_sk:
xor ecx,ecx
inc ecx
ret


start:
mov esi,offset string1
call atoi

invoke ExitProcess,0
end start