# File lib/thor/util.rb, line 221
      def ruby_command
        @ruby_command ||= begin
          ruby_name = RbConfig::CONFIG['ruby_install_name']
          ruby = File.join(RbConfig::CONFIG['bindir'], ruby_name)
          ruby << RbConfig::CONFIG['EXEEXT']

          # avoid using different name than ruby (on platforms supporting links)
          if ruby_name != 'ruby' && File.respond_to?(:readlink)
            begin
              alternate_ruby = File.join(RbConfig::CONFIG['bindir'], 'ruby')
              alternate_ruby << RbConfig::CONFIG['EXEEXT']

              # ruby is a symlink
              if File.symlink? alternate_ruby
                linked_ruby = File.readlink alternate_ruby

                # symlink points to 'ruby_install_name'
                ruby = alternate_ruby if linked_ruby == ruby_name || linked_ruby == ruby
              end
            rescue NotImplementedError
              # just ignore on windows
            end
          end

          # escape string in case path to ruby executable contain spaces.
          ruby.sub!(/.*\s.*/m, '"\&"')
          ruby
        end
      end