Joy of Think

Today, I am trying to use festival c/c++ api to say a word. After checking document, I decided to write an extension for ruby.
It is a simple task. All your need to do is:

Write a extension c file.

This file must define a function:
void Init_your_module_name()
It will be called on ruby loading it.
require "your_module_name"

In this function, generally, you must have following codes:


VALUE rb_mFestivalTTS;

rb_mFestivalTTS = rb_define_module( "FestivalTTS" ); //Define a module.
rb_define_module_function( rb_mFestivalTTS, "say", say, 1 ); //Define a function in module.


Write a extconf.rb

# extconf.rb
require 'mkmf'

dir_config('your_package_name')
create_makefile('your_package_name')


You can use find_library and find_header to add library and include path.

Run "make" command.


ruby extconf.rb
make


But it is a complex task too.

mkmf.rb doesn't support C

You must stick to C language.

You must be familiar with Ruby internal

All value passed bewteen extension and ruby inteperator is VALUE. It has a lot of api to manipuate VALUE. You must study <ruby.h>

Especially, you can use VALUE as a string by: StringValueCStr().