Using Mac Sudden Motion Sensor with RubyInline

require 'rubygems'
require "inline"
class SMS
  class << self
    inline do |builder|
      builder.add_compile_flags '-x objective-c', '-framework IOKit'
      builder.include "&lt;IOKit/IOKitLib.h>"
      builder.c %q{
        VALUE values(){

          struct data {
            unsigned short x;
            unsigned short y;
            unsigned short z;
            char pad[34];
          };

          kern_return_t result;

          mach_port_t masterPort;
          IOMasterPort(MACH_PORT_NULL, &masterPort);
          CFMutableDictionaryRef matchingDictionary = IOServiceMatching("SMCMotionSensor");

          io_iterator_t iterator;
          result = IOServiceGetMatchingServices(masterPort, matchingDictionary, &iterator);

          if(result != KERN_SUCCESS) {
            return rb_str_new2("Error");
          }

          io_object_t device = IOIteratorNext(iterator);
          IOObjectRelease(iterator);
          if(device == 0){
            return rb_str_new2("Error");
          }

          io_connect_t dataPort;
          result = IOServiceOpen(device, mach_task_self(), 0, &dataPort);
          IOObjectRelease(device);

          if(result != KERN_SUCCESS) {
            return rb_str_new2("Error");
          }

          IOItemCount structureInputSize;
          IOByteCount structureOutputSize;

          struct data inputStructure;
          struct data outputStructure;
          structureInputSize = sizeof(struct data);
          structureOutputSize = sizeof(struct data);

          memset(&inputStructure, 1, sizeof(inputStructure));
          memset(&outputStructure, 0, sizeof(outputStructure));

          result = IOConnectMethodStructureIStructureO(
            dataPort,
            5,
            structureInputSize,
            &structureOutputSize,
            &inputStructure,
            &outputStructure
          );

          if(result != KERN_SUCCESS) {
            return rb_str_new2("Error");
          }

          IOServiceClose(dataPort);

          VALUE coords = rb_ary_new2(3);
          rb_ary_store(coords, 0, INT2FIX(outputStructure.x));
          rb_ary_store(coords, 1, INT2FIX(outputStructure.y));
          rb_ary_store(coords, 2, INT2FIX(outputStructure.z));

        return coords;
        }
      }
    end
  end
end
loop do
  x,y,z = SMS.values
  puts "#{x} #{y} #{z}"
end