From: Park Heesob <phasis68@...>
Date: 2006-03-18T16:16:52+09:00
Subject: Re: Win32API struct member help


Hi,
>
>Hi all,
>
>I'm trying to figure out how to get the acl attributes of a simple text
>file, and I need a little help getting data out of a struct.
>Specifically, I need to get the AceCount from an access control list
>(ACL struct) after a call to GetSecurityDescriptorDacl().  Here's what
>I've got so far:
>
>
>require 'Win32API'
>
>
...
>
>acl_ptr = [0].pack('L') # what should this be?
>
>
>val = GetSecurityDescriptorDacl.call(
>   sec_buf,
>   dacl_present,
>   acl_ptr,
>   dacl_defaulted
>)
>
>
>if val == 0
>   raise ArgumentError, 'GetSecurityDescriptorDacl failed'
>end
>
>
>p acl_ptr.unpack('CCSSS') # [228, 50, 632, nil, nil]
>
>
>I was expecting 4 for the 4th attribute (AceCount).  I tried changing
>the initial value of acl_ptr to [0,0,0,0,0].pack('CCSSS') but that
>didn't help.  What did I do wrong?
>
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')

Regards,

Park Heesob