From: warhero <beingthexemplarylists@...>
Date: 2006-12-05T05:00:08+09:00
Subject: Re: utilizing dlls in windows programming?

Thanks, do you have previous experience with Phidgets and ruby?



On Dec 4, 5:00 am, "Park Heesob" <phasi...@hotmail.com> wrote:
> Hi,
>
> >From: "warhero" <beingthexemplaryli...@gmail.com>
> >Reply-To: ruby-t...@ruby-lang.org
> >To: ruby-t...@ruby-lang.org (ruby-talk ML)
> >Subject: utilizing dlls in windows programming?
> >Date: Mon, 4 Dec 2006 14:55:07 +0900
>
> >This is a two part question:
>
> >I have been reading the pick-axe book and was reading the chapter on
> >ruby and windows. I was reading documentation on the DL library. (is
> >library the correct term for that?), but my question: what is the
> >difference in the Win32API and using say DL.dlopen? Also in reading the
> >documentation on the Win32API in the back of the book, it said that
> >Win32API is more than likely going to be phased out.Refer tohttp://weblog.jamisbuck.org/2004/12/30/disappointments-in-ruby-land
> andhttp://rubyforge.org/pipermail/win32utils-devel/2005-February/000294....
>
>
>
>
>
> >My second question:
>
> >I am trying to utilize a DLL that is for phidgets (phidgets.com). They
> >have a dll (phidget21.dll) that is supposed to be used to gain access
> >to controlling their hardware. I've looked at their documentation for
> >the C language. Is that usually what a dll is written in? C? You can
> >download what I am looking at from the documentation section. (The C
> >API Manual ). I've tried a couple of different ways to try and use the
> >dll. Nothing as succeeded. I've tried the Win32API and the DL.dlopen.
> >It's probably just the way i'm trying to use it. here is what im
> >trying:
>
> >require "dl"
> >Phidget21 = DL.dlopen("phidget21");
> >f = Phidget21["CPhidgetRFID_create", "S"]
> >handle = f.call()
> >open = Phidget21["CPhidget_open", "II"]
> >open.call( 25807 )
>
> >The first problem is that handle = nil. Besides that, I don't
> >understand fully how to be passing back and forth parameters to the
> >dlls. This example cause the interactive ruby to crash (terminates in
> >an unusual way). I know this isn't all that's needed to work with the
> >phidgets, but i'm just trying to go step by step and even get it setup
> >correctly.
>
> >download the phidget21.dll
> >(http://www.smithaaronlee.net/downloads/phidget21.dll), i've posted the
> >dll online. Also, here is a direct link to the C API
> >:http://www.phidgets.com/documentation/C_API_Manual_Phidget21.pdf
>
> >any help, hints or tips would be much appreciated.The following code will work for you:
>
> require 'dl'
> Phidget21 = DL.dlopen('phidget21')
> CPhidgetRFID_create = Phidget21['CPhidgetRFID_create', 'LP']
> handleptr = [0].pack('L').to_ptr
> CPhidgetRFID_create.call(handleptr)
> handle = handleptr.to_i
> CPhidget_open = Phidget21['CPhidget_open', 'ILI']
> CPhidget_open.call( handle,-1 )
>
> Or
>
> require 'Win32API'
> CPhidgetRFID_create =
> Win32API.new('phidget21.dll','CPhidgetRFID_create','P','I')
> CPhidget_open = Win32API.new('phidget21.dll','CPhidget_open','LI','I')
> handleptr = [0].pack('L')
> CPhidgetRFID_create.call(handleptr)
> handle = handleptr.unpack('L')[0]
> CPhidget_open.call(handle,-1)
>
> Regards,
>
> Park Heesob
>
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