ruby-ffi

http://wiki.github.com/ffi/ffi

Ruby-FFI is a ruby extension for programmatically loading dynamic libraries, binding functions within them, and calling those functions from Ruby code. Moreover, a Ruby-FFI extension works without changes on Ruby and JRuby. Discover why should you write your next extension using Ruby-FFI here.

• It has a very intuitive DSL

• It supports all C native types

• It supports C structs (also nested), enums and global variables

• It supports callbacks

• It has smart methods to handle memory management of pointers and structs

require 'ffi'

module MyLib
  extend FFI::Library
  ffi_lib 'c'
  attach_function :puts, [ :string ], :int
end

MyLib.puts 'Hello, World using libc!'

For less minimalistic and more sane examples you may look at:

• the samples/ folder

• the examples on the wiki

• the projects using FFI listed on this page

• You need a sane building environment in order to compile the extension.

From rubyforge:

[sudo] gem install ffi

or from the git repository on github:

git clone git://github.com/ffi/ffi.git
cd ffi
rake gem:install

See LICENSE file.