######################################################################
    DNS::ZoneParse 1.10
######################################################################

NAME
    DNS::ZoneParse - Parse and manipulate DNS Zone Files.

SYNOPSIS
        use DNS::ZoneParse;
    
        my $zonefile = DNS::ZoneParse->new("/path/to/dns/zonefile.db", $origin);
    
        # Get a reference to the MX records
        my $mx = $zonefile->mx;
    
        # Change the first mailserver on the list
        $mx->[0] = { host => 'mail.localhost.com',
                     priority => 10,
                     name => '@' };
    
        # update the serial number
        $zonefile->new_serial();
    
        # write the new zone file to disk 
        my $newzone;
        open($newzone, '>', '/path/to/dns/zonefile.db') or die "error";
        print $newzone $zonefile->output();
        close $newzone;

INSTALLATION
       perl Makefile.PL
       make
       make test
       make install

    Win32 users substitute "make" with "nmake" or equivalent. nmake is
    available at
    http://download.microsoft.com/download/vc15/Patch/1.52/W95/EN-US/Nmake15
    .exe

DESCRIPTION
    This module will parse a Zone File and put all the Resource Records
    (RRs) into an anonymous hash structure. Various record types are
    supported, see the methods section for details. It could be useful for
    maintaining DNS zones, or for transferring DNS zones to other servers.
    If you want to generate an XML-friendly version of your zone files, it
    is easy to use XML::Simple with this module once you have parsed the
    zone file.

    DNS::ZoneParse scans the DNS zone file - removes comments and seperates
    the file into its constituent records. It then parses each record and
    stores the records internally. See below for information on the accessor
    methods.

  METHODS
    new This creates the DNS::ZoneParse object and loads the zone file.

        Example: my $zonefile = DNS::ZoneParse->new("/path/to/zonefile.db");

        You can also initialise the object with the contents of a file: my
        $zonefile = DNS::ZoneParse->new( \$zone_contents );

        You can pass a second, optional parameter to the constructor to
        supply an $origin if none can be found in the zone file.

            my $zonefile = DNS::ZoneParse->new( \$zone_contents, $origin );

        You can pass a third, optional parameter to the constructor to
        supply a callback which will be called whenever an unparsable line
        is encountered in the zone file. See "on_unparseable_line" for
        details on this parameter and how errors are handled when parsing
        zone files.

        If you plan to pass a on_unparseable_line callback but do not wish
        to specify an $origin, pass 'undef' as the $origin parameter.

    a(), cname(), srv(), mx(), ns(), ptr(), txt(), hinfo(), rp(), loc()
        These methods return references to the resource records. For
        example:

            my $mx = $zonefile->mx;

        Returns the mx records in an array reference.

        All records (except SOA) have the following properties: 'ttl',
        'class', 'host', 'name', 'ORIGIN'.

        MX records also have a 'priority' property.

        SRV records also have 'priority', 'weight' and 'port' properties.

        TXT records also have a 'text' property representing the record's
        'txt-data' descriptive text.

        HINFO records also have 'cpu' and 'os' properties.

        RP records also have 'mbox' and 'text' properties.

        LOC records also have 'd1', 'm1', 's1', 'NorS', 'd2', 'm2', 's2',
        'EorW', 'alt', 'siz', 'hp', and 'vp', as per RFC 1876.

        If there are no records of a given type in the zone, the call will
        croak with an error message about an invalid method. (This is not an
        ideal behavior, but has been kept for backwards compatibility.)

        The 'ORIGIN' property is the fully-qualified origin of the record.
        See fqname for details on constructing a fully qualified domain
        name. Note: for SOA records, the 'ORIGIN' will match the 'origin'
        property when the SOA record is specified as fully qualified.

    soa()
        Returns a hash reference with the following properties: 'serial',
        'origin', 'primary', 'refresh', 'retry', 'ttl', 'minimumTTL',
        'email', 'expire', 'class', 'ORIGIN'.

        The 'ORIGIN' property is returned separate from 'origin' property,
        though the data may be the same. 'ORIGIN' represents the implicit
        origin for the record while 'origin' represents the origin specified
        on the SOA line in the file.

        If the 'origin' value is relative (that is, does not end with a
        '.'), the actual zone for which the SOA line applies must be
        computed by concatenating the 'origin' and 'ORIGIN' values. See
        fqname for details. If the 'origin' value is absolute, no
        computation is necessary and 'origin' is the same as 'ORIGIN'.

    generate()
        Returns an array of hashes representing $GENERATE directives present
        in the zone. Note, $GENERATE directives are BIND-specific additions.
        They are not expanded by DNS::ZoneParse, but users are able to
        access and modify these directives. The following properties are
        returned:

        'range', 'lhs', 'ttl', 'class', 'type', 'rhs', 'ORIGIN'.

        See the BIND documentation for details on the syntax and usage of
        the $GENERATE directive.

    dump
        Returns a copy of the datastructute that stores all the resource
        records. This might be useful if you want to quickly transform the
        data into another format, such as XML.

    fqname
        Takes a single parameter, a hash reference containing a record.

        Returns the fully qualified name of this record, with a trailing
        '.'. In most cases this is as simple as concatenating the 'name' and
        'ORIGIN' with a '.' unless 'name' is '@', in which case the fqname
        is simply the 'ORIGIN'. For SOA records, the same process is
        performed on the 'origin' instead of 'name'.

        Please note, fqname will not expand the right hand side of a record
        (ie, CNAME, SOA, MX, etc). The user must expand these values via the
        above method.

    ttl_to_int
        Takes a single parameter, a string representing a valid record TTL.

        Returns an integer representing the number of seconds the TTL
        represents. Note, this does not take into account any leap-years,
        leap-seconds, DST changes, etc. It is simply the count of the number
        of seconds in the specified period of time.

    new_serial
        "new_serial()" incriments the Zone serial number. It will generate a
        date-based serial number. Or you can pass a positive number to add
        to the current serial number.

        Examples:

            $zonefile->new_serial(); 
                    # generates a new serial number based on date:
                    # YYYYmmddHH format, incriments current serial
                    # by 1 if the new serial is still smaller

            $zonefile->new_serial(50);  
                    # adds 50 to the original serial number

    output
        "output()" returns the new zone file output as a string. If you wish
        your output formatted differently, you can pass the output of
        "dump()" to your favourite templating module.

    last_parse_error_count
        Returns a count of the number of unparsable lines from the last time
        a zone file was parsed. If no zone file has been parsed yet, returns
        0.

        If you want to be sure that a zone file was parsed completely and
        without error, the return value of this method should be checked
        after the constructor is called (or after a call to _parse).

    on_unparseable_line
        "on_unparseable_line()" is an accessor method for the callback used
        when an unparseable line is encountered while parsing a zone file.
        If not set, DNS::ZoneParse will "croak" when an unparsable line is
        encountered, but will continue to parse the file. Each time an
        unparsable line is encountered, an internal counter is incrememnted.
        See "last_parse_error_count" for details.

        The callback is passed four parameters, a reference to the
        DNS::ZoneParse object which is doing the parsing, the text of the
        line that is unable to be parsed, the text of the reason the line
        could not be parsed, and the text of the last successfully parsed
        line.

        If you want to abort parsing when an unparsable line is found, call
        "die" from within your callback and catch that die with an eval
        block around the DNS::ZoneParse constructor (or call to _parse).

        The method takes a single optional parameter, a code reference to
        the function that will be called when an unparsable line is reached.
        Returns a reference to the last callback. If passed an undefined
        value, a reference to the current callback is returned. If passed
        any other value, undef is returned.

  EXAMPLES
    This script will print the A records in a zone file, add a new A record
    for the name "new" and then return the zone file.

        use strict;
        use DNS::ZoneParse;
    
        my $zonefile = DNS::ZoneParse->new("/path/to/zonefile.db");
    
        print "Current A Records\n";
        my $a_records = $zonefile->a();
    
        foreach my $record (@$a_records) {
            print "$record->{name} resolves at $record->{host}\n";
        }
    
        push (@$a_records, { name => 'new', class => 'IN',
                             host => '127.0.0.1', ttl => '' });
    
        $zonefile->new_serial();
        my $newfile = $zonefile->output();

    This script will convert a DNS Zone file to an XML file using
    XML::Simple.

        use strict;
        use DNS::ZoneParse;
        use XML::Simple;

        my $zonefile = DNS::ZoneParse->new("/path/to/zonefile.db");

        my $new_xml = XMLout($zonefile->dump,
                             noattr => 1,
                             suppressempty => 1,
                             rootname => $zonefile->origin);

CHANGES
    See Changes

API
    The DNS::ZoneParse API may change in future versions. At present, the
    parsing is not as strict as it should be and support for $ORIGIN and
    $TTL is quite basic. It would also be nice to support the "INCLUDE"
    statement. Furthermore, parsing large zone files with thousands of
    records can use lots of memory - some people have requested a callback
    interface.

BUGS
    I can squash more bugs with your help. Please let me know if you spot
    something that doesn't work as expected.

    You can report bugs via the CPAN RT:
    <http://rt.cpan.org/NoAuth/Bugs.html?Dist=DNS-ZoneParse>

    If possible, please provide a diff against t/dns-zoneparse.t and
    t/test-zone.db that demonstrates the bug(s).

SEE ALSO
    Other modules with similar functionality:

    Net::DNS::ZoneParser, Net::DNS::ZoneFile, DNS::ZoneFile

AUTHOR
    Simon Flack

MAINTENANCE
    Maintainers: Mike Schilli ([email protected]), John Eaglesham
    ([email protected]).

    Bug queue:
    http://rt.cpan.org/Public/Dist/Display.html?Name=DNS-ZoneParse

LICENSE
    DNS::ZoneParse is free software which you can redistribute and/or modify
    under the same terms as Perl itself.