Return a list of valid arguments.

def getargs():
    """
    Return a list of valid arguments.
    """
    parser = argparse.ArgumentParser(description='\
    Select paths from a directory tree.')
    parser.add_argument("-a", "--hidden", action="store_false",
                        help="Show all hidden paths too.")
    parser.add_argument("-r", "--relative", action="store_true",
                        help="Output relative paths.")
    parser.add_argument("path", type=chkpath, nargs='?',
                        default=".", help="A valid path.")
    return parser.parse_args()