crequire

A simply way to require c code in ruby using SWIG.

Dependencies

• ruby 1.9
• make
• SWIG

A simple example

If you have a header file then the functions are detected automatically. You can either define the functions in the header file or define a header and implementation file separately.

example1.h

int fact(int n) {
  if (n <= 1) return 1;
  else return n * fact(n-1);
}

void swap(int *a, int *b) {
  int tmp;
  tmp = *b;
  *b = *a;
  *a = tmp;
}

test_example1.rb

require "crequire"
crequire "example1"
include Example1

fact(4) => 24

a = Intp.new
a.assign 1
b = Intp.new
b.assign 2

swap(a, b)

a.value => 2
b.value => 1

A complex example

If you don't define a header file, you must pass in a block to define the method signatures.

example2.c

int sum(int a, int b) {
  return a + b;
}

void add(int *x, int *y, int *r) {
  *r = *x + *y;
}

char* echo(char* word) {
  return word;
}

test_example2.rb

require "crequire"

# :force => true forces a compile on every run. Alternatively, you can delete
# the 'example2.o' file for a recompile.

crequire "example2", :force => true do
  # To define a function signature, declare the type followed by the function
  # name, passing in the types as symbols or strings.

  int sum(:int, :int)

  # To make working with pointers easer, you can define them as *INPUT or
  # *OUTPUT.

  void add("int *INPUT", "int *INPUT", "int *OUTPUT")

  # char* is automatically converted to and from string
  char* echo("char*")
end

include Example2

sum(1, 2) => 3
add(3, 4) => 7
echo("hi") => "hi"

Advanced Options

You can use :src => string to pass in the contents of the interface file directly.

example2.c

int sum(int a, int b, int times) {
  int result = a;
  for (int i = 0; i < times; i++) {
    result += b;
  }
  return result;
}

test_example3.rb

require 'crequire'

# ```:interface => directory``` outputs the generated interface file to the given
# directory. If you want to dump all generated files, you can use
# ```:dump => directory```.


interface = "%module example3 
%{ 
extern int sum(int a, int b, int times);
%}
extern int sum(int a, int b, int times);" 

# You can use ```:cflags => flags``` to set c compiler options.
crequire "example3", :force => true, :cflags => "-std=c99", :interface => "example3", :src => interface

include Example3

sum(1, 2, 2) => 5

example3/example3.i

%module example3
%{
extern int sum(int a, int b);
%}
extern int sum(int a, int b);

Contributing to crequire

• Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet
• Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it
• Fork the project
• Start a feature/bugfix branch
• Commit and push until you are happy with your contribution
• Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright

Copyright (c) 2011 Evan Tatarka. See LICENSE.txt for further details.