From: Park Heesob <phasis@...>
Date: 2003-12-31T09:30:40+09:00
Subject: Re: Win32API question: accessing a PBOOL

Hi,
From: "Phil Tomson" <intc_ctor@yahoo.com>

>
> I'm trying to call:
> (from MSDN info):
> " BOOL IsWow64Process(
>    HANDLE hProcess,
>    PBOOL Wow64Process
>  );
>
> Parameters
>
> hProcess
>     [in] Handle to a process.
> Wow64Process
>     [out] Pointer to a value that is set to TRUE if the process is
> running under WOW64. Otherwise, the value is set to FALSE.
>
> Return Values
>
> If the function succeeds, the return value is a nonzero value.
>
> If the function fails, the return value is zero."
>
> I can see that return value is 1 meaning that the call succeeded, but
> I can't seem to get anything out of the Wow64Process parameter.
>
> Here's the code snippet:
>
> #########Should work on WinXP, other Wins will skip the relevant code
> ######
> require 'Win32API'
> begin
>   #only works on XP which is why we rescue:
>   Is64bit  = Win32API.new("kernel32","IsWow64Process",['L','P'],'L')
> rescue
>   puts "you're not on XP"
>   Is64bit = nil
>   isXP    = false
> else
>   puts "you're on XP, but is it 64 bit?"
>   isXP    = true
> end
> #Now try to see if we're running on WinXP 64bit edition:
>   is64 = "f" #string to pass into the Wow64Process param
>   if isXP
>     puts "Possibly 64bit.  Checking..."
>     result = Is64bit.call(GetCurrentProcess.call(),is64)
>     #is64 should be false on WinXP and true on WinXP-64bit#
>     puts "result is: #{result}, is64 is #{is64.unpack("L")}"
>   else
>     puts "Not 64bit"
>   end
> #########end########
>
> What I see (when it runs on an XP-64 box) is:
>
> result is: 1, is64 is
>
> So I can't seem to determine the result in the is64 param; I'd expect
> either a 0 or 1.
>
> What am I doing wrong?
>
> Phil
>
>
 I think the pointer type is 32 bit.

Here is sample code for
"BOOL GetSystemTimeAdjustment(
  PDWORD lpTimeAdjustment,
  PDWORD lpTimeIncrement,
  PBOOL lpTimeAdjustmentDisabled
);"

====================================
require 'Win32API'


  getSystemTimeAdjustment  =
Win32API.new("kernel32","GetSystemTimeAdjustment",['P','P','P'],'L')

  lpTimeAdjustment = "\0" * 4
  lpTimeIncrement = "\0" * 4
  lpTimeAdjustmentDisabled = "\0" * 4

  p
getSystemTimeAdjustment.Call(lpTimeAdjustment,lpTimeIncrement,lpTimeAdjustme
ntDisabled)
  p lpTimeAdjustment.unpack("L")[0]
  p lpTimeIncrement.unpack("L")[0]
  p lpTimeAdjustmentDisabled.unpack("L")[0]
=========================================

Regards,

Park Heesob