From: Daniel Berger <djberg96@...>
Date: 2006-03-19T03:08:48+09:00
Subject: Re: Win32API struct member help

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')

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
      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?

Thanks,

Dan