def ruby_executable
      @ruby_executable ||= begin
        dir, name, ext = CONFIG.values_at(*%w[bindir RUBY_INSTALL_NAME EXEEXT])
        ::File.join(dir, name + ext).sub(/.*\s.*/m, '"\&"')
      end
    end
def ruby_executable
      @ruby_executable ||= begin
        dir, name, ext = CONFIG.values_at(*%w[bindir RUBY_INSTALL_NAME EXEEXT])
        ::File.join(dir, name + ext).sub(/.*\s.*/m, '"\&"')
      end
    end
Returns the full path to the current Ruby interpreter's executable file.
 This might not be the actual correct command to use for invoking the Ruby
 interpreter; use ruby_command instead.