def main():
    '''Base58 encode or decode FILE, or standard input, to standard output.'''

    import sys
    import argparse

    stdout = buffer(sys.stdout)

    parser = argparse.ArgumentParser(description=main.__doc__)
    parser.add_argument(
        'file',
        metavar='FILE',
        nargs='?',
        type=argparse.FileType('r'),
        default='-')
    parser.add_argument(
        '-d', '--decode', action='store_true', help='decode data')
    parser.add_argument(
        '-c',
        '--check',
        action='store_true',
        help='append a checksum before encoding')

    args = parser.parse_args()
    fun = {
        (False, False): b58encode,
        (False, True): b58encode_check,
        (True, False): b58decode,
        (True, True): b58decode_check
    }[(args.decode, args.check)]

    data = buffer(args.file).read().rstrip(b'\n')

    try:
        result = fun(data)
    except Exception as e:
        sys.exit(e)

    if not isinstance(result, bytes):
        result = result.encode('ascii')

    stdout.write(result)
Base58 encode or decode FILE, or standard input, to standard output.