22

def split (origin, fqdn):

    33

def relative (origin, domain, name) :

    34

    """

    35

        relative relative label @origin for name@domain

    36

    37

        Raises ValueError if name is outside of origin

    38

    39

        >>> print relative(None, None, 'fqdn')

    40

        fqdn.

    41

        >>> print relative(None, 'domain', 'host')

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        host.domain.

    43

        >>> print relative('origin', 'domain', 'host')

    44

        Traceback (most recent call last):

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            ...

    46

        ValueError: host: domain domain out of zone origin.

    47

        >>> print relative('origin', 'origin', 'host')

    48

        host

    49

        >>> print relative('origin', 'domain.origin', 'host')

    50

        host.domain

    51

        >>> print relative('origin', 'domainorigin', 'host')

    52

        Traceback (most recent call last):

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            ...

    54

        ValueError: host: domain domainorigin out of zone origin.

    55

        >>> print relative('origin', None, 'host.domain')

    56

        Traceback (most recent call last):

    57

            ...

    58

        ValueError: host.domain: fqdn host.domain. out of zone origin.

    59

    """

    60

    61

    if origin:

    62

        origin = fqdn(origin)

    63

    64

    if domain:

    65

        host_fqdn = fqdn(name, domain)

    66

    else:

    67

        host_fqdn = fqdn(name)

    68

    69

    70

    if not origin:

    71

        return host_fqdn

    72

    73

    elif domain == origin:

    74

         return name

    75

    76

    elif host_fqdn.endswith('.' + origin):

    77

        return split(origin, host_fqdn)

    78

    79

    elif domain:

    80

        raise ValueError("{name}: domain {domain} out of zone {origin}".format(name=name, domain=domain, origin=origin))

    81

    82

    else:

    83

        raise ValueError("{name}: fqdn {fqdn} out of zone {origin}".format(name=name, fqdn=host_fqdn, origin=origin))

    84

    85