Executes the external command and get its exitcode, stdout and stderr
        
        :return: exit code of command

def get_exit_code(self):
        """Executes the external command and get its exitcode, stdout and stderr
        
        :return: exit code of command
        """
        args = shlex.split(self.cmd)

        proc = Popen(args, stdout=PIPE, stderr=PIPE)
        out, err = proc.communicate()
        out, err = out.decode("utf8"), err.decode("utf8")
        exitcode = proc.returncode
        #
        return exitcode, out, err