clidriver.py 文件源码

def main(self, args=None):
        """

        :param args: List of arguments, with the 'aws' removed.  For example,
            the command "aws s3 list-objects --bucket foo" will have an
            args list of ``['s3', 'list-objects', '--bucket', 'foo']``.

        """
        if args is None:
            args = sys.argv[1:]
        command_table = self._get_command_table()
        parser = self._create_parser(command_table)
        self._add_aliases(command_table, parser)
        parsed_args, remaining = parser.parse_known_args(args)
        try:
            # Because _handle_top_level_args emits events, it's possible
            # that exceptions can be raised, which should have the same
            # general exception handling logic as calling into the
            # command table.  This is why it's in the try/except clause.
            self._handle_top_level_args(parsed_args)
            self._emit_session_event()
            return command_table[parsed_args.command](remaining, parsed_args)
        except UnknownArgumentError as e:
            sys.stderr.write("usage: %s\n" % USAGE)
            sys.stderr.write(str(e))
            sys.stderr.write("\n")
            return 255
        except NoRegionError as e:
            msg = ('%s You can also configure your region by running '
                   '"aws configure".' % e)
            self._show_error(msg)
            return 255
        except NoCredentialsError as e:
            msg = ('%s. You can configure credentials by running '
                   '"aws configure".' % e)
            self._show_error(msg)
            return 255
        except KeyboardInterrupt:
            # Shell standard for signals that terminate
            # the process is to return 128 + signum, in this case
            # SIGINT=2, so we'll have an RC of 130.
            sys.stdout.write("\n")
            return 128 + signal.SIGINT
        except Exception as e:
            LOG.debug("Exception caught in main()", exc_info=True)
            LOG.debug("Exiting with rc 255")
            err = get_stderr_text_writer()
            err.write("\n")
            err.write(six.text_type(e))
            err.write("\n")
            return 255