From: intc_ctor@... (Phil Tomson)
Date: 2003-12-31T05:26:48+09:00
Subject: Win32API question: accessing a PBOOL

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