Input an Integer

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Pjuu

Joined: 03 Apr 2005
Posts: 2
Location: England, UK

Pjuu 03 Apr 2005, 15:58

Hiya

I am writing a very simple compiler just as a small project and it is going
to translate to FASM assembly language. I have most of it sorted i was
just wondering how i can get a few things sorted.

How can i check what has been inputted into a buffer from the ReadFile
routine in Kernel32 is a valid integer? And how i could convert this string
into an integer. I have been trying for a while now and can not do it i need
it to take into account negative numbers and if the input is not an integer
to throw a nice error message. Could any one please help?

Thanks in advance Wink

_________________
Pjuu ^__^

03 Apr 2005, 15:58

coconut

Joined: 02 Apr 2004
Posts: 326
Location: US

coconut 03 Apr 2005, 19:36

have you looked at wsprintf? http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/resources/strings/stringreference/stringfunctions/wsprintf.asp

03 Apr 2005, 19:36

kidscracker

Joined: 29 Oct 2004
Posts: 46

kidscracker 03 Apr 2005, 19:47

Here is a code that will work, i tok it from an old 16bit library and adapt it, I forgot the part where it detects if it's and negative number Confused

, but i will post it later. te code is:

Code:

proc    STR_ToLong,lptrString
        enter
        push    ecx edx esi
        pushfd
        cld
        xor     ecx,ecx

        mov     esi,[lptrString]

;
.lp:
        lodsb
        xor     al, '0'
        cmp     al, 10
        ja      .NotDigit
        shl     ecx, 1
        jc      .Error
        mov     edx, ecx
        shl     ecx, 1
        jc      .Error
        shl     ecx, 1
        jc      .Error
        add     ecx, edx
        jc      .Error
        add     cl, al
        adc     ch, 0
        jc      .Error
        jmp     .lp
;
.NotDigit:
        mov     eax,ecx
        popfd
        pop     esi edx ecx
        clc
        return
;
.Error:
        popfd
        pop     esi edx ecx
        stc
        return
endp

I hope it will be helpufull

03 Apr 2005, 19:47

Pjuu

Joined: 03 Apr 2005
Posts: 2
Location: England, UK

Pjuu 05 Apr 2005, 10:03

Thanks this has been a big help. I am happy that you have shown me a quicker comparison way in my failed attempts the code was kinda huge Razz

THANKS!

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Pjuu ^__^

05 Apr 2005, 10:03

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