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64 bit assembler => 64 Bit Assembler => Topic started by: Gunther on October 01, 2012, 12:48:35 AM

Title: Is it printf or _printf?
Post by: Gunther on October 01, 2012, 12:48:35 AM

I need some help for the Windows 64 bit environment. Since I haven't running a 64 bit windows, I hope one of the members can answer. If one would call the LIBC from an assembly language application, is it:

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call printfor

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call _printf
Thank you.

Gunther

Title: Re: Is it printf or _printf?
Post by: qWord on October 01, 2012, 01:17:47 AM

it is printf.

Title: Re: Is it printf or _printf?
Post by: Vortex on October 01, 2012, 03:53:56 AM

Also, the same is true for msvcrt.dll. The function is exported as printf

Title: Re: Is it printf or _printf?
Post by: Gunther on October 01, 2012, 09:22:00 AM

Thank you for the information. In the 32 bit world it's _printf.

Gunther

Title: Re: Is it printf or _printf?
Post by: jj2007 on October 01, 2012, 03:27:47 PM

Quote from: Gunther on October 01, 2012, 09:22:00 AM

Thank you for the information. In the 32 bit world it's _printf.

Gunther

In the Masm32 world it seems to be printf: call crt_printf ;)

Title: Re: Is it printf or _printf?
Post by: MichaelW on October 01, 2012, 03:31:05 PM

Quote from: Gunther on October 01, 2012, 09:22:00 AM

In the 32 bit world it's _printf.

I know for some CRTs it is, the lcclibc.dll that I tested recently for example, but for MSVCRT.dll, on my Windows 2000 system and on my Windows XP system, it’s “printf”.

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;==============================================================================
; Build as a console app.
;==============================================================================
include \masm32\include\masm32rt.inc
;==============================================================================
.data
    hMod dd 0
.code
;==============================================================================
start:
;==============================================================================
    invoke LoadLibrary, chr$("msvcrt.dll")
    mov hMod, eax
    printf("%Xh\n",hMod)
    invoke GetProcAddress, hMod, chr$("printf")
    mov ebx, eax
    printf("%Xh\n\n",ebx)

    push ebx
    push cfm$("%Xh\n\n")
    call ebx
    add esp, 8

    inkey
    exit
;==============================================================================
end start


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78023626h

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