1Net::DNS::RR(3)       User Contributed Perl Documentation      Net::DNS::RR(3)
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3
4

NAME

6       Net::DNS::RR - DNS Resource Record class
7

SYNOPSIS

9       "use Net::DNS::RR"
10

DESCRIPTION

12       "Net::DNS::RR" is the base class for DNS Resource Record (RR) objects.
13       See also the manual pages for each RR type.
14

METHODS

16       WARNING!!!  Don't assume the RR objects you receive from a query are of
17       a particular type -- always check an object's type before calling any
18       of its methods.  If you call an unknown method, you'll get a nasty
19       warning message and "Net::DNS::RR" will return "undef" to the caller.
20
21   new (from string)
22        $a     = Net::DNS::RR->new("foo.example.com. 86400 A 10.1.2.3");
23        $mx    = Net::DNS::RR->new("example.com. 7200 MX 10 mailhost.example.com.");
24        $cname = Net::DNS::RR->new("www.example.com 300 IN CNAME www1.example.com");
25        $txt   = Net::DNS::RR->new('baz.example.com 3600 HS TXT "text record"');
26
27       Returns a "Net::DNS::RR" object of the appropriate type and initialized
28       from the string passed by the user.  The format of the string is that
29       used in zone files, and is compatible with the string returned by
30       "Net::DNS::RR->string".
31
32       The name and RR type are required; all other information is optional.
33       If omitted, the TTL defaults to 0 and the RR class defaults to IN.
34       Omitting the optional fields is useful for creating the empty RDATA
35       sections required for certain dynamic update operations.  See the
36       "Net::DNS::Update" manual page for additional examples.
37
38       All names must be fully qualified.  The trailing dot (.) is optional.
39
40   new (from hash)
41        $rr = Net::DNS::RR->new(
42                name    => "foo.example.com",
43                ttl     => 86400,
44                class   => "IN",
45                type    => "A",
46                address => "10.1.2.3",
47        );
48
49        $rr = Net::DNS::RR->new(
50                name => "foo.example.com",
51                type => "A",
52        );
53
54       Returns an RR object of the appropriate type, or a "Net::DNS::RR"
55       object if the type isn't implemented.  See the manual pages for each RR
56       type to see what fields the type requires.
57
58       The "Name" and "Type" fields are required; all others are optional.  If
59       omitted, "TTL" defaults to 0 and "Class" defaults to IN.  Omitting the
60       optional fields is useful for creating the empty RDATA sections
61       required for certain dynamic update operations.
62
63       The fields are case-insensitive, but starting each with uppercase is
64       recommended.
65
66   parse
67           ($rrobj, $offset) = Net::DNS::RR->parse(\$data, $offset);
68
69       Parses a DNS resource record at the specified location within a DNS
70       packet.  The first argument is a reference to the packet data.  The
71       second argument is the offset within the packet where the resource
72       record begins.
73
74       Returns a Net::DNS::RR object and the offset of the next location in
75       the packet.
76
77       Parsing is aborted if the object could not be created (e.g., corrupt or
78       insufficient data).
79
80   print
81           $rr->print;
82
83       Prints the record to the standard output.  Calls the string method to
84       get the RR's string representation.
85
86   string
87           print $rr->string, "\n";
88
89       Returns a string representation of the RR.  Calls the rdatastr method
90       to get the RR-specific data. Domain names are returned in RFC1035
91       format, i.e. all non letter, digit, hyphen characters are represented
92       as \DDD.
93
94   rdatastr
95           $s = $rr->rdatastr;
96
97       Returns a string containing RR-specific data.  Subclasses will need to
98       implement this method.
99
100   name
101           $name = $rr->name;
102
103       Returns the record's domain name.
104
105   type
106           $type = $rr->type;
107
108       Returns the record's type.
109
110   class
111           $class = $rr->class;
112
113       Returns the record's class.
114
115   ttl
116           $ttl = $rr->ttl;
117
118       Returns the record's time-to-live (TTL).
119
120   rdlength
121           $rdlength = $rr->rdlength;
122
123       Returns the length of the record's data section.
124
125   rdata
126           $rdata = $rr->rdata
127
128       Returns the record's data section as binary data.
129

Sorting of RR arrays

131       As of version 0.55 there is functionality to help you sort RR arrays.
132       The sorting is done by Net::DNS::rrsort(), see the Net::DNS
133       documentation. This package provides class methods to set the sorting
134       functions used for a particular RR based on a particular attribute.
135
136   set_rrsort_func
137       Net::DNS::RR::SRV->set_rrsort_func("priority",
138       sub {                        my ($a,$b)=($Net::DNS::a,$Net::DNS::b);
139                              $a->priority <=> $b->priority
140                              ||                        $b->weight <=>
141       $a->weight
142                            }
143
144       Net::DNS::RR::SRV->set_rrsort_func("default_sort",
145       sub {                        my ($a,$b)=($Net::DNS::a,$Net::DNS::b);
146                              $a->priority <=> $b->priority
147                              ||                        $b->weight <=>
148       $a->weight
149                            }
150
151       set_rrsort_func needs to be called as a class method. The first
152       argument is the attribute name on which the sorting will need to take
153       place. If you specify "default_sort" than that is the sort algorithm
154       that will be used in the case that rrsort() is called without an RR
155       attribute as argument.
156
157       The second argument is a reference to a function that uses the
158       variables $a and $b global to the "from Net::DNS"(!!)package for the
159       sorting. During the sorting $a and $b will contain references to
160       objects from the class you called the set_prop_sort from. In other
161       words, you can rest assured that the above sorting function will only
162       get Net::DNS::RR::SRV objects.
163
164       The above example is the sorting function that actually is implemented
165       in SRV.
166

BUGS

168       This version of "Net::DNS::RR" does little sanity checking on user-
169       created RR objects.
170
172       Copyright (c) 1997-2002 Michael Fuhr.
173
174       Portions Copyright (c) 2002-2004 Chris Reinhardt.
175
176       Portions Copyright (c) 2005-2007 Olaf Kolkman
177
178       Portions Copyright (c) 2007 Dick Franks
179
180       All rights reserved.  This program is free software; you may
181       redistribute it and/or modify it under the same terms as Perl itself.
182
183       EDNS0 extensions by Olaf Kolkman.
184

SEE ALSO

186       perl(1), Net::DNS, Net::DNS::Resolver, Net::DNS::Packet,
187       Net::DNS::Update, Net::DNS::Header, Net::DNS::Question, RFC 1035
188       Section 4.1.3
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192perl v5.12.0                      2009-01-26                   Net::DNS::RR(3)
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