Skip to content


Subversion checkout URL

You can clone with
Download ZIP
C Assembly Shell Ruby TeX Makefile Other
Failed to load latest commit information.
bench fix tests for netbsd
ext/ffi_c methodHandleParamTypes needs to refer to valid memory after rbffi_Met…
gen Keep a log of generated types.conf files
lib bump to 1.9.10
libtest Add specs for non int enum arguments
nbproject Add custom data converters for parameter and return types
samples Fix qsort example for 64bit
spec fix struct specs on 1.8
.gitignore ignore Gemfile.lock
.travis.yml tweak travis to allow failure in 2.2 on osx
COPYING Switch license to BSD throughout codebase. See #288.
Gemfile Update version of rake-compiler-dock to 0.4.0.
LICENSE Switch license to BSD throughout codebase. See #288.
LICENSE.SPECS Change licensing of the specs to the same license as Rubyspec fixed small typo in Readme
ffi.gemspec Update version of rake-compiler-dock to 0.4.0.

ruby-ffi Build Status


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 you should write your next extension using Ruby-FFI.


  • Intuitive DSL
  • Supports all C native types
  • C structs (also nested), enums and global variables
  • Callbacks from C to ruby
  • Automatic garbage collection of native memory


require 'ffi'

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

MyLib.puts 'Hello, World using libc!'

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


You need a sane building environment in order to compile the extension. At a minimum, you will need:

  • A C compiler (e.g. Xcode on OSX, gcc on everything else)
  • libffi development library - this is commonly in the libffi-dev or libffi-devel


From rubygems:

[sudo] gem install ffi

or from the git repository on github:

git clone git://
cd ffi
rake gem:install


The ffi library is covered by the BSD license, also see the LICENSE file. The specs are shared with Rubyspec and are licensed by the same license as Rubyspec, see the LICENSE.SPECS file.


The following people have submitted code, bug reports, or otherwise contributed to the success of this project:

Something went wrong with that request. Please try again.