From: Dennis Ranke <exoticorn@...>
Date: 2004-01-11T21:41:38+09:00
Subject: Re: dereferencing pointers in Win32 API

On Sat, 10 Jan 2004 14:43:19 -0600, Shashank Date <sdate@everestkc.net> 
wrote:

>> If I'm not completely wrong, you should be able to dereference it using
>> lpBuffer.unpack('P<size>') where <size> is the size of the buffer in
>> bytes. Just remember that unpack returns an array, the first element of
>> which will be the dereferenced buffer as a string.
>
> I tried that and i get:
>
> C:/atest/tst_netapi32.rb:28:in `unpack': no associated pointer
> (ArgumentError)
>  from C:/atest/tst_netapi32.rb:28

You are right, after reading the relevant ruby source, it seems that you 
can only dereference pointers that you have written into the string 
yourself using Array#pack('P'). So the suggestion of Park to use memcpy 
might be your best bet.

As a sidenote to matz:

Is it intentional that String#unpack('P') can raise both
"no associated pointer" (when the string doesn't have any associates)
and
"non associated pointer" (then the string does have associates, but this 
pointer isn't among them)?

-- 
Dennis Ranke