import re
import string


def sanitize_name(name):
    """
    Sanitize a given name such that it conforms to unix policy.
    Args:
        name: the name to sanitize.
    Returns:
        The sanitized form of name.
    """

    if len(name) == 0:
        raise Exception("Can not sanitize an empty field.")

    sanitized_name = re.sub(r"[^a-z0-9\+-]", "-", name.lower())

    if sanitized_name[0] in string.digits:
        sanitized_name = "p" + sanitized_name

    return sanitized_name