Ruby-FFI https://github.com/ffi/ffi/wiki 
Ruby-FFI is a gem for programmatically loading dynamically-linked native libraries, binding functions within them, and calling those functions from Ruby code. Moreover, a Ruby-FFI extension works without changes on CRuby (MRI), JRuby, Rubinius and TruffleRuby. 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
end
MyLib.puts 'Hello, World using libc!'For less minimalistic and more examples you may look at:
- the
samples/folder - the examples on the wiki
- the projects using FFI listed on the wiki: https://github.com/ffi/ffi/wiki/projects-using-ffi
When installing the gem on CRuby (MRI), you will need:
- A C compiler (e.g., Xcode on macOS,
gccorclangon everything else) Optionally (speeds up installation): - The
libffilibrary and development headers - this is commonly in thelibffi-devorlibffi-develpackages
The ffi gem comes with a builtin libffi version, which is used, when the system libffi library is not available or too old. Use of the system libffi can be enforced by:
gem install ffi -- --enable-system-libffi # to install the gem manually
bundle config build.ffi --enable-system-libffi # for bundle install
or prevented by --disable-system-libffi.
On Linux systems running with PaX (Gentoo, Alpine, etc.), FFI may trigger mprotect errors. You may need to disable mprotect for ruby (paxctl -m [/path/to/ruby]) for the time being until a solution is found.
On FreeBSD systems pkgconf must be installed for the gem to be able to compile using clang. Install either via packages pkg install pkgconf or from ports via devel/pkgconf.
On JRuby and TruffleRuby, there are no requirements to install the FFI gem, and require 'ffi' works even without installing the gem (i.e., the gem is preinstalled on these implementations).
From rubygems:
[sudo] gem install ffi
or from the git repository on github:
git clone git://github.com/ffi/ffi.git
git submodule update --init --recursive
cd ffi
rake install
The ffi library is covered by the BSD license, also see the LICENSE file. The specs are covered by the same license as ruby/spec, the MIT license.
The following people have submitted code, bug reports, or otherwise contributed to the success of this project:
- Alban Peignier alban.peignier@free.fr
- Aman Gupta aman@tmm1.net
- Andrea Fazzi andrea.fazzi@alcacoop.it
- Andreas Niederl rico32@gmx.net
- Andrew Cholakian andrew@andrewvc.com
- Antonio Terceiro terceiro@softwarelivre.org
- Benoit Daloze eregontp@gmail.com
- Brian Candler B.Candler@pobox.com
- Brian D. Burns burns180@gmail.com
- Bryan Kearney bkearney@redhat.com
- Charlie Savage cfis@zerista.com
- Chikanaga Tomoyuki nagachika00@gmail.com
- Hongli Lai hongli@phusion.nl
- Ian MacLeod ian@nevir.net
- Jake Douglas jake@shiftedlabs.com
- Jean-Dominique Morani jdmorani@mac.com
- Jeremy Hinegardner jeremy@hinegardner.org
- Jesús García Sáez blaxter@gmail.com
- Joe Khoobyar joe@ankhcraft.com
- Jurij Smakov jurij@wooyd.org
- KISHIMOTO, Makoto ksmakoto@dd.iij4u.or.jp
- Kim Burgestrand kim@burgestrand.se
- Lars Kanis kanis@comcard.de
- Luc Heinrich luc@honk-honk.com
- Luis Lavena luislavena@gmail.com
- Matijs van Zuijlen matijs@matijs.net
- Matthew King automatthew@gmail.com
- Mike Dalessio mike.dalessio@gmail.com
- NARUSE, Yui naruse@airemix.jp
- Park Heesob phasis@gmail.com
- Shin Yee shinyee@speedgocomputing.com
- Stephen Bannasch stephen.bannasch@gmail.com
- Suraj N. Kurapati sunaku@gmail.com
- Sylvain Daubert sylvain.daubert@laposte.net
- Victor Costan
- beoran@gmail.com
- ctide christide@christide.com
- emboss Martin.Bosslet@googlemail.com
- hobophobe unusualtears@gmail.com
- meh meh@paranoici.org
- postmodern postmodern.mod3@gmail.com
- wycats@gmail.com wycats@gmail.com
- Wayne Meissner wmeissner@gmail.com