From: intc_ctor@... (Phil Tomson)
Date: 2003-12-31T09:56:48+09:00
Subject: Re: (FYI)Accessing WinXP-64bit registry items

ptkwt@aracnet.com (Phil Tomson) wrote in message news:<bsqqb502b3k@enews4.newsguy.com>...
> In article <c68ca8f2.0312291659.7c864268@posting.google.com>,
> Phil Tomson <intc_ctor@yahoo.com> wrote:
> >There probably aren't a lot of WinXP-64bit users out there yet, but I
> >post this for future reference:
> >
> >I was using the win32/registry (as in 'require "win32/registry"')
> >package to access the registry to figure out if certiain apps were
> >installed on a Windows box.  The script worked fine on my Win2K box,
> >but when someone tried it on their WinXP-64bit edition box it didn't
> >find the installed apps as it should have.
> >
> >Turns out that in 64bit windows there are two sections to the
> >registry, a 32bit section and a 64bit section.  I couldn't see the
> >64bit apps from the Ruby script (using the standard Ruby install
> >created by Andy Hunt, so it's 32 bits).  After some research, I found
> >out that you've got to add some new registry access rights.
> >
> >The solution is that you need to add some new access rights keys in
> >your Win32::Registry::Constants module:
> >
> >      KEY_WOW64_64KEY = 0x0100
> >      KEY_WOW64_32KEY = 0x0200
> >
> >And then OR them into KEY_READ:
> >
> >      KEY_READ = STANDARD_RIGHTS_READ | KEY_WOW64_64KEY |
> >KEY_WOW64_32KEY |
> >        KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS | KEY_NOTIFY
> >
> >After I did that it worked fine ? I was able to see the 64bit registry
> >entries.
> >
> >How's that for obscure? ;-)
> >
> >You can find more info here:
> >
> >http://msdn.microsoft.com/library/default.asp?url=/library/enus/sysinfo/base/registry_key_security_and_access_rights.asp
> >
> >I've notified Usa Nakamura who I'm told is the registry.rb maintainer,
> >so hopefully, by the time you need this in the 64bit future it will
> >work OK out of the box.
> >
> 
> Well, I spoke a bit too soon...  Sure it works on 64-bit Windows, but it 
> breaks now on 32-bit Windows.
> 
> Looks like we need to come up with some reliable way to determine if 
> you're running on 64bit WinXP or 32Bit WinXP and then do something like:
> 
>   KEY_READ |= (KEY_WOW64_64KEY | KEY_WOW64_32KEY)  if XP64
> 
> Any ideas for how to determine XP64?
> 

Here's what I had to do to determine if the script is running on
WinXP64 (changes to win32/registry.rb):


require 'Win32API'
module Win32
  class Registry
    module Constants
       #since IsWow64Process only exists on XP we need to do
       #a rescue in case we're not running on an XP machine:
       begin
	 IsWow64Process=Win32API.new("kernel32","IsWow64Process",['L','P'],'L')
       rescue
	 puts "you're not on XP"  if $DEBUG
         isXP    = false
       else
         puts "you're on XP: could be 32 or 64 bit"  if $DEBUG
         isXP    = true
       end
  
      GetCurrentProcess =
Win32API.new("kernel32","GetCurrentProcess",[],'L')

#<snipage>

      KEY_WOW64_64KEY = 0x0100
      KEY_WOW64_32KEY = 0x0200
      key_read = STANDARD_RIGHTS_READ | 
        KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS | KEY_NOTIFY
      if isXP
        is64 = ""
	result = IsWow64Process.call(GetCurrentProcess.call(),is64)
	is64 = true if is64.unpack("c")[0].to_i != 0
	if is64
          puts "This script is running on WinXP 64bit edition" if
$DEBUG
	  key_read |= (KEY_WOW64_64KEY | KEY_WOW64_32KEY )
	end
      end      
      KEY_READ = key_read

#<snipage>

    end
  end
end
########


Now this works on WinXP or NOT(WinXP) Windows boxen.

Phil