From: daz <dooby@...10.karoo.co.uk>
Date: 2005-11-02T05:43:06+09:00
Subject: Re: Using LoadLibrary from within an extension


From: David Koontz

> I am having an issue where LoadLibrary works fine on my system in a normal C
> application but not inside an extension (it always returns NULL no matter
> what).  The same call (translated to dlopen) works fine under linux though so
> I'm not sure if it's a specific issue to Windows extensions.  For testing
> purposes I'm loading a hard coded library but under linux I have also tested
> passing in the name and that works fine.  Here's the function that's being
> called from Ruby along with the relevant variable declarations and imports.
>
> [...]
>
> library_handle = LoadLibrary("alleg40.dll");


This dll must be in your Windows PATH or the current working dir.

Perhaps, when you ran your C app., they were in the same dir -
(the dir from which the app was loaded is added to the search path).
From Ruby, the Ruby path is not searched by LoadLibrary
but you can use:

  Dir.chdir('C:\path\to\alleg40')
before:
  require 'my_ext'

... which sets the current working dir (also added to the search path).

I don't know of any other issue that could cause the load to fail.


daz

(btw: not a -core issue ... [ruby-talk] knows C ;)