From: Park Heesob <phasis68@...>
Date: 2006-03-19T12:30:24+09:00
Subject: Re: Win32API struct member help

Hi,


>From: "Daniel Berger" <djberg96@gmail.com>
>Reply-To: ruby-talk@ruby-lang.org
>To: ruby-talk@ruby-lang.org (ruby-talk ML)
>Subject: Re: Win32API struct member help
>Date: Sun, 19 Mar 2006 03:08:48 +0900
>
>Park Heesob wrote:
> > Hi,
>
><snip>
>
> > memcpy is required for pointer reference,try this:
> >
> > memcpy = Win32API.new('msvcrt','memcpy','PLL','P')
> > acl_buf = "\0" * 8
> > memcpy.call(acl_buf,acl_ptr.unpack('L')[0],8)
> > p acl_buf.unpack('CCSSS')
>
>Ok, along the same lines, I'm having some trouble with GetAce().  Using
>'acl_buf' from above:
>
>GetAce = Win32API.new('advapi32', 'GetAce', 'PLP', 'I')
>

   GetAce = Win32API.new('advapi32', 'GetAce', 'LLP', 'I')

>ace_count = acl_buf.unpack('CCSSS')[3] # 4
>ace_ptr  = [0].pack('L')
>
>0.upto(ace_count - 1){ |i|
>    if GetAce.call(acl_buf, i, ace_ptr) == 0

      if GetAce.call(acl_ptr.unpack('L')[0], i, ace_ptr) == 0

>       next
>    end
>
>    ace_buf = 0.chr * 4 # 2 BYTE, 1 WORD
>    memcpy.call(ace_buf, ace_ptr.unpack('L').first, 4)
>
>    # This doesn't return the values I would have expected
>    p ace_buf.unpack('CCS')
>}
>
>I would have expected somewhere between 20 and 40 for the third element
>of the array returned by ace_buf.unpack('CCS'), but instead I'm getting
>0.  What am I doing wrong this time?
>
I guess GetAce requires more than acl buffer. GetAce works with original 
pointer ace_ptr.

Regards,

Park Heesob