"""Top-level implementation of the helloworld program."""

import argparse

import sys

import helloworld

parser = argparse.ArgumentParser(

description='A simple example program to print a friendly greeting.')

parser.add_argument('--version', action='version',

version='helloworld ' + helloworld.__version__)

def main(argv=None):

if argv is None:

argv = sys.argv

# The helloworld program doesn't expect any arguments.

# This just checks for the special --version and --help arguments and

# ensures the user hasn't passed any other unrecognized arguments.

parser.parse_args(argv[1:])

print("Hello, world")

return 0