import argparse

if __name__ == '__main__':
    desc = '''
        An example of how to use argparse

        ./CMD SUBCOMMAND [options...]

        SUB COMMANDS:
            record
            report
            ...
	'''

    arg_parser = argparse.ArgumentParser(description=desc)

    sub_parser = arg_parser.add_subparsers(dest='sub_cmd')

    sub_init = sub_parser.add_parser('record',
                                     help='Record')
    sub_init.add_argument('-i', '--ip',
                          action='store',
                          required=True,
                          help='hostname for target')
    sub_init.add_argument('--user',
                          action='store',
                          metavar='USER',
                          default='root',
                          help='User name for a target')
    sub_init.add_argument('--port',
                          action='store',
                          type=int,
                          default=22,
                          help='Port for a target')
    sub_init.add_argument('--append',
                          action='store_true',
                          help='Append traced data')

    sub_report = sub_parser.add_parser('report',
                                       help='Report helper')
    sub_report.add_argument('--filter-pid', action='store',
                            nargs='*',
                            type=int,
                            metavar='PID',
                            help='Filter PIDs')

    args = arg_parser.parse_args()

    # If subcommand doesn't exist?
    if not args.sub_cmd:
        arg_parser.print_help()
        exit(0)

    if args.sub == 'record':
        # Do something
        pass
    elif args.sub == 'report':
        # Do something
        pass