# File lib/mkmf-gnome2.rb, line 151
def ruby_gnome2_version(glib_source_directory=nil)
  glib_source_directory ||= File.join(File.dirname(__FILE__), "..",
                                      "ext", "glib2")
  rbglib_h = File.join(glib_source_directory, "rbglib.h")
  return nil unless File.exist?(rbglib_h)

  version = nil
  File.open(rbglib_h) do |h_file|
    version_info = {}
    h_file.each_line do |line|
      case line
      when /\A#define RBGLIB_(MAJOR|MINOR|MICRO)_VERSION\s+(\d+)/
        version_info[$1] = $2
      end
    end
    version_info = [version_info["MAJOR"],
                    version_info["MINOR"],
                    version_info["MICRO"]].compact
    version = version_info.join(".") if version_info.size == 3
  end

  version
end