CSC/ECE 517 Spring 2014/ch1 1w1h jg

Ruby libraries to load objects of other languages at run time

Ruby is a dynamic, reflective, object-oriented, general-purpose programming language. It is easy to extend Ruby with new features by writing code in Ruby. But every now and then extending ruby with low-level languages, such asC/C++/Java is also necessary.

Currently, various kinds of languages codes could be invoked from within ruby. The extension for C/C++ and Java are focused here.

Ruby C/C++ extensions<ref>http://java.ociweb.com/mark/NFJS/RubyCExtensions.pdf</ref>

By extending Ruby with C. The C libraries could be used directly in Ruby applications. Ruby could call C codes in three ways: interpreter API, RubyInline, SWIG.

interpreter API

Ruby interpreter is implemented in C, its API can be used and no special API added for interacting with C like Java’s JNI is needed.

• mkmf (make makefile) Ruby Module

For this usage, platform-specific Makefiles for compiling C extensions to Ruby is needed to be generated firstly.

A simple sample is like below:

create a file containing the following, named extconf.rb by convention

require 'mkmf'
extension_name = 'name'
dir_config(extension_name)
create_makefile(extension_name)

And use by running

ruby extconf.rb
make

Then generates

.so under UNIX/Linux
.so under Windows when building with Cygwin
.bundle under Mac OS X