You probably know that FFI enables you to use existing and custom native libraries by writing only Ruby code.

You probably know that a Ruby FFI extension is multi-platform, multi-implementation and will work without changes on Ruby, JRuby, and any other Ruby implementation that supports FFI.

You may even know that FFI has been part of JRuby for awhile.

But you may not know that mswin32 and mingw32 binary MRI RubyGems exist for Windows users *and* they support both 1.8 and 1.9 environments.  Installation is just a "gem install ffi" away!

While using FFI with the Windows API works great, documentation has been a bit sparse.  We'd like to change this and have started to collect typical usage examples at http://wiki.github.com/ffi/ffi/windows-examples

The goal of the wiki page is not to try to cover everything or show off just puzzler-style code. Rather, we'd like to provide common examples for the use cases you'll likely encounter when working with the Windows API from Ruby.  You know, the 80% story.

So what's the point to all of this?

We'd like more real-world Windows FFI examples and I'm asking for your help in adding these examples, especially intermediate and advanced level examples.

Guidelines
==========
1) Show off "core" examples that can be conceptually reused 
2) Try to keep the C part of the example to less than 35 LOC
3) Take relevant shortcuts in favor of highlighting the core idea (eg - full FFI::Struct definition really needed?) 
4) Add unnecessary code (e.g. - free) if it hilites fundamental FFI behavior
5) Confirm that your C code compiles and runs
6) Validate that your Ruby FFI code runs on MRI 1.8, 1.9 and JRuby in 1.8 and 1.9 modes
7) Reuse the side-by-side Textile wiki markup sections for your examples

Feel free to edit the wiki page but be warned that the Textile + HTML + inline CSS is twitchy and non-DRY. I'm pushing the wiki page past what it was meant to do, but don't be scared off as GitHub version controls these pages...it's really hard to really mess things up.

If you have a cool contribution, but can't update the wiki page, please create a http://gist.github.com/ or a http://pastie.org/ or an email and reply back to this message on our Google Group at http://groups.google.com/group/ruby-ffi

Thanks!

Jon