Net::DNS::RR(3pm) User Contributed Perl Documentation Net::DNS::RR(3pm)NAMENet::DNS::RR - DNS Resource Record base class
SYNOPSIS
use Net::DNS;
$rr = new Net::DNS::RR('example.com IN A 192.0.2.99');
$rr = new Net::DNS::RR(
name => 'example.com'
type => 'A',
address => '192.0.2.99'
);
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!!! Do not assume the RR objects you receive from a query are
of a particular type -- always check the object type before calling any
of its methods. If you call an unknown method, you will get an error
message and execution will be terminated.
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",
);
$rr = Net::DNS::RR->new(
name => "foo.example.com",
type => "A",
);
Returns an RR object of the appropriate type, or a "Net::DNS::RR"
object if the type isn't implemented. See the manual pages for each RR
type to see what fields the type requires.
The "Name" and "Type" fields are required; all others are optional. If
omitted, "TTL" defaults to 0 and "Class" defaults to IN. Omitting the
optional fields is useful for creating the empty RDATA sections
required for certain dynamic update operations.
The fields are case-insensitive, but starting each with uppercase is
recommended.
decode
($rrobj, $offset) = Net::DNS::RR->decode(\$data, $offset);
Decodes 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.
Decoding 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. Domain names arereturned in RFC1035
format, i.e. all non letter, digit, hyphen characters are represented
as \DDD. Besides, all domain names are expanded to fully qualified
domain names, with trailing dot. This is in contrast to accessor
methods of individual data elements in RR objects, like name, which
will not return the trailing dot.
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, Net::DNS, Net::DNS::Resolver, Net::DNS::Packet, Net::DNS::Update,
Net::DNS::Header, Net::DNS::Question, RFC 1035 Section 4.1.3
perl v5.18.1 2012-01-27 Net::DNS::RR(3pm)
