Here is a well known code to simulate printf :
include \masm32\include\masm32rt.inc
.code
printfX PROC C format:DWORD,arglist:VARARG
LOCAL buffer[512]:BYTE
LOCAL hHandle:DWORD
LOCAL BytesWritten:DWORD
invoke GetStdHandle,STD_OUTPUT_HANDLE
mov hHandle,eax
invoke wvsprintf,ADDR buffer,format,ADDR arglist
push eax
lea ecx,BytesWritten
invoke WriteFile,hHandle,ADDR buffer,eax,ecx,0
pop eax
ret
printfX ENDP
END
Testing the function :
include Test.inc
.data
frmt db '%s %d',0
str1 db 'This is test',0
.code
start:
invoke printfX,ADDR frmt,ADDR str1,1
invoke ExitProcess,0
END start
Unfortunately w[v]sprintf does not support floating point types.
Quote from: qWord on February 12, 2014, 10:36:58 AM
Unfortunately w[v]sprintf does not support floating point types.
right, but swprintf (http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/index.jsp?topic=%2Frtref%2Fswprintf.htm) (with leading s) can be used for that.
Gunther
Quote from: Gunther on February 12, 2014, 11:36:50 PMright, but swprintf (http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/index.jsp?topic=%2Frtref%2Fswprintf.htm) (with leading s) can be used for that.
right, but in this case one could directly call printf/wprintf.
Quote from: qWord on February 13, 2014, 02:53:21 AM
right, but in this case one could directly call printf/wprintf.
of course.
Gunther
wsprintf and wvsprintf are useful functions exported by user32.dll Why MS didn't support floating point, that's very strange.
Quote from: Vortex on February 13, 2014, 06:07:18 AM
wsprintf and wvsprintf are useful functions exported by user32.dll Why MS didn't support floating point, that's very strange.
Even ntdll.dll sprinft doesn't support float ?
In MS there must be those academic HardCore men's who want make things always in HandWork manner ;)
Real man doesn't need floats, just Budwiser :badgrin:
TWell,
Quote from: TWell on February 13, 2014, 07:12:05 AM
Real man doesn't need floats, just Budwiser :badgrin:
but the real Budweiser please, not that muck from overseas.
Gunther
So you all are aware of what a big stink Micro$oft makes over getting you
not to use this function, right?
Under "Security Considerations" for this function description, they say:
QuoteUsing this function incorrectly can compromise the security of your application. The string returned in lpOut is not guaranteed to be null-terminated. Also, avoid the %s format -- it can lead to a buffer overrun. If an access violation occurs it causes a denial of service against your application. In the worse case, an attacker can inject executable code. Consider using one of the following alternatives: StringCbPrintf, StringCbPrintfEx, StringCbVPrintf, StringCbVPrintfEx, StringCchPrintf, StringCchPrintfEx, StringCchVPrintf, or StringCchVPrintfEx.
Myself, I just ignore all this hoo-hah and use the damn thing anyhow (but then, I'm not writing production code and don't have to answer to users whose systems might be corrupted because of my program). What do others think of this?
See the function description
here (http://msdn.microsoft.com/en-us/library/windows/desktop/ms647550(v=vs.85).aspx).
Quote from: NoCforMe on March 01, 2014, 02:45:03 PMMyself, I just ignore all this hoo-hah and use the damn thing anyhow. What do others think of this?
We are assembly programmers, so we know exactly what our code does. You need to be actively dumb to cause a buffer overrun ;-)
(Personally, I only use Print (http://www.webalice.it/jj2006/MasmBasicQuickReference.htm#Mb1110) - safe and versatile)
Quote from: jj2007 on March 01, 2014, 06:29:53 PMYou need to be actively dumb to cause a buffer overrun ;-)
Or actively malicious.
Quote from: Gunther on February 13, 2014, 03:46:50 AM
Quote from: qWord on February 13, 2014, 02:53:21 AM
right, but in this case one could directly call printf/wprintf.
of course.
Gunther
You are a man of many words. :biggrin:
Andy
Real men code in assembly. :) :) :)
Hi NoCforMe,
welcome to the forum.
Quote from: Vortex on March 01, 2014, 08:50:01 PM
Real men code in assembly. :) :) :)
Right.
Quote from: Magnum on March 01, 2014, 08:10:29 PM
You are a man of many words. :biggrin:
Andy
That's my style, Andy. :lol:
Gunther