From: Park Heesob <phasis68@...>
Date: 2006-06-08T19:00:56+09:00
Subject: Re: using an inout parameter from a DLL


Hi,

>From: Xavier Noria <fxn@hashref.com>
>Reply-To: ruby-talk@ruby-lang.org
>To: ruby-talk@ruby-lang.org (ruby-talk ML)
>CC: Ana Isabel L?ez <ailopez@aspgems.com>
>Subject: using an inout parameter from a DLL
>Date: Thu, 8 Jun 2006 18:12:19 +0900
>
>I have to call a function in a DLL using the dl library.
>
>That function returns a status value and has a pointer to long as  inout 
>parameter to return a value if successful. How do I declare  that type? How 
>do I pass that parameter? How do I read the value  pointed to?
>
>-- fxn
>
>
A little ugly but this works:

msg = DL.dlopen("dlltest.dll")
@func= msg["Func", "IL"]

in_value = 123
ptr = [in_value].pack('L')
a = @func.call( [ptr].pack("P").unpack('L').first )
out_value = ptr.unpack('L').first


Regards,

Park Heesob