<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def main():
 # pragma: nocover """Print checksum and file name for all files in the directory. """

    p = argparse.ArgumentParser(add_help="Recursively list interesting files.")
    p.add_argument(
        'directory', nargs="?", default="",
        help="The directory to process (current dir if omitted)."
    )
    p.add_argument(
        '--verbose', '-v', action='store_true',
        help="Increase verbosity."
    )

    args = p.parse_args()
    args.curdir = os.getcwd()
    if not args.directory:
        args.direcotry = args.curdir
    if args.verbose:
        print(args)

    for chsm, fname in list_files(args.directory):
        print(chsm, fname)