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Net::DNS::RR(3pm)     User Contributed Perl Documentation    Net::DNS::RR(3pm)



NAME
       Net::DNS::RR - DNS Resource Record class

SYNOPSIS
       "use Net::DNS::RR"

DESCRIPTION
       "Net::DNS::RR" is the base class for DNS Resource Record (RR) objects.
       See also the manual pages for each RR type.

METHODS
       WARNING!!!  Don't assume the RR objects you receive from a query are of
       a particular type -- always check an object's type before calling any
       of its methods.  If you call an unknown method, you'll get a nasty
       warning message and "Net::DNS::RR" will return "undef" to the caller.

       new (from string)

        $a     = Net::DNS::RR->new("foo.example.com. 86400 A 10.1.2.3");
        $mx    = Net::DNS::RR->new("example.com. 7200 MX 10 mailhost.example.com.");
        $cname = Net::DNS::RR->new("www.example.com 300 IN CNAME www1.example.com");
        $txt   = Net::DNS::RR->new('baz.example.com 3600 HS TXT "text record"');

       Returns a "Net::DNS::RR" object of the appropriate type and initialized
       from the string passed by the user.  The format of the string is that
       used in zone files, and is compatible with the string returned by
       "Net::DNS::RR->string".

       The name and RR type are required; all other information is optional.
       If omitted, the TTL defaults to 0 and the RR class defaults to IN.
       Omitting the optional fields is useful for creating the empty RDATA
       sections required for certain dynamic update operations.  See the
       "Net::DNS::Update" manual page for additional examples.

       All names must be fully qualified.  The trailing dot (.) is optional.

       new (from hash)

        $rr = Net::DNS::RR->new(
                name    => "foo.example.com",
                ttl     => 86400,
                class   => "IN",
                type    => "A",
                address => "10.1.2.3",
        );

        $rr = Net::DNS::RR->new(
                name => "foo.example.com",
                type => "A",
        );

       Returns an RR object of the appropriate type, or a "Net::DNS::RR"
       object if the type isn't implemented.  See the manual pages for each RR
       type to see what fields the type requires.

       The "Name" and "Type" fields are required; all others are optional.  If
       omitted, "TTL" defaults to 0 and "Class" defaults to IN.  Omitting the
       optional fields is useful for creating the empty RDATA sections
       required for certain dynamic update operations.

       The fields are case-insensitive, but starting each with uppercase is
       recommended.

       parse

           ($rrobj, $offset) = Net::DNS::RR->parse(\$data, $offset);

       Parses a DNS resource record at the specified location within a DNS
       packet.  The first argument is a reference to the packet data.  The
       second argument is the offset within the packet where the resource
       record begins.

       Returns a Net::DNS::RR object and the offset of the next location in
       the packet.

       Parsing is aborted if the object could not be created (e.g., corrupt or
       insufficient data).

       print

           $rr->print;

       Prints the record to the standard output.  Calls the string method to
       get the RR's string representation.

       string

           print $rr->string, "\n";

       Returns a string representation of the RR.  Calls the rdatastr method
       to get the RR-specific data.

       rdatastr

           $s = $rr->rdatastr;

       Returns a string containing RR-specific data.  Subclasses will need to
       implement this method.

       name

           $name = $rr->name;

       Returns the record's domain name.

       type

           $type = $rr->type;

       Returns the record's type.

       class

           $class = $rr->class;

       Returns the record's class.

       ttl

           $ttl = $rr->ttl;

       Returns the record's time-to-live (TTL).

       rdlength

           $rdlength = $rr->rdlength;

       Returns the length of the record's data section.

       rdata

           $rdata = $rr->rdata

       Returns the record's data section as binary data.

Sorting of RR arrays
       As of version 0.55 there is functionality to help you sort RR arrays.
       The sorting is done by Net::DNS::rrsort(), see the Net::DNS
       documentation. This package provides class methods to set the sorting
       functions used for a particular RR based on a particular attribute.

       set_rrsort_func

       Net::DNS::RR::SRV->set_rrsort_func("priority",
       sub {                        my ($a,$b)=($Net::DNS::a,$Net::DNS::b);
                              $a->priority <=> $b->priority
                              ||                        $b->weight <=>
       $a->weight
                            }

       Net::DNS::RR::SRV->set_rrsort_func("default_sort",
       sub {                        my ($a,$b)=($Net::DNS::a,$Net::DNS::b);
                              $a->priority <=> $b->priority
                              ||                        $b->weight <=>
       $a->weight
                            }

       set_rrsort_func needs to be called as a class method. The first
       argument is the attribute name on which the sorting will need to take
       place. If you specify "default_sort" than that is the sort algorithm
       that will be used in the case that rrsort() is called without an RR
       attribute as argument.

       The second argument is a reference to a function that uses the
       variables $a and $b global to the "from Net::DNS"(!!)package for the
       sorting. During the sorting $a and $b will contain references to
       objects from the class you called the set_prop_sort from. In other
       words, you can rest assured that the above sorting function will only
       get Net::DNS::RR::SRV objects.

       The above example is the sorting function that actually is implemented
       in SRV.

BUGS
       This version of "Net::DNS::RR" does little sanity checking on user-
       created RR objects.

COPYRIGHT
       Copyright (c) 1997-2002 Michael Fuhr.

       Portions Copyright (c) 2002-2004 Chris Reinhardt.

       Portions Copyright (c) 2005-2007 Olaf Kolkman

       Portions Copyright (c) 2007 Dick Franks

       All rights reserved.  This program is free software; you may
       redistribute it and/or modify it under the same terms as Perl itself.

       EDNS0 extensions by Olaf Kolkman.

SEE ALSO
       perl(1), Net::DNS, Net::DNS::Resolver, Net::DNS::Packet,
       Net::DNS::Update, Net::DNS::Header, Net::DNS::Question, RFC 1035
       Section 4.1.3



perl v5.10.0                      2008-02-15                 Net::DNS::RR(3pm)