Net::DNS::Domain(3)

NAME
    Net::DNS::Domain - Domain Name System domains

SYNOPSIS
    use Net::DNS::Domain

DESCRIPTION
The "Net::DNS::Domain" module implements a class of abstract DNS domain objects with associated class and instance methods.

Each domain object instance represents a single DNS domain which has a fixed identity throughout its lifetime.

Internally, the primary representation is a (possibly empty) list of ASCII domain labels, and optional link to an ancestor domain object topologically closer to the root of the DNS namespace.

The presentation form of the domain name is generated on demand and the result cached within the object.

METHODS

  new
    $domain = new Net::DNS::Domain('example.com');

Creates a domain object which represents the DNS domain identified by the character string argument. The identifier consists of a sequence of labels delimited by dots.

The argument string consists of printable characters from the 7-bit ASCII repertoire.

A character preceded by \ represents itself, without any special interpretation.

Any 8-bit code point can be represented by \ followed by exactly three decimal digits. Character code points are ASCII, irrespective of the encoding employed by the underlying platform. No characters are associated with code points beyond 127.

Argument strings should be delimited by single quotes to avoid escape sequences being misinterpreted by the compiler.

The character string presentation format follows the conventions for zone files described in RFC1035.

  decode
    $domain = decode Net::DNS::Domain( \$buffer, $offset, $hash );

    ( $domain, $next ) = decode Net::DNS::Domain( \$buffer, $offset, $hash );

Creates a domain object which represents the DNS domain identified by the compressed name at the indicated offset within the data buffer.

The argument list consists of a reference to a scalar containing the wire-format data, specified offset and reference to a hash used to represent compressed names.

The returned offset value indicates the start of the next item in the data buffer.

  encode
    $data = $domain->encode( $offset, $hash );

Returns the wire-format representation of the domain object suitable for inclusion in a DNS packet buffer.

The optional arguments are the offset within the packet data where the domain name is to be stored and a reference to a hash table used to index compressed names within the packet.

  name
    $name = $domain->name;

Returns a character string corresponding to the "typical" form of domain name to which section 11 of RFC2181 alludes.

The string consists of printable characters from the 7-bit ASCII repertoire. Code points outside this set are represented by the appropriate numerical escape sequence.

  mailbox
    $mail = $domain->mailbox;

Returns a character string containing the mailbox interpretation of the domain name as described in RFC1035 section 8.

  string
    $fqdn = $domain->string;

Returns a character string containing the absolute name of the domain as described in RFC1035 section 5.1.

The string consists of printable characters from the 7-bit ASCII repertoire. Code points outside this set are represented by the appropriate numerical escape sequence.

Characters which have special meaning in a zone file, dots which are part of a domain label, and the escape character itself are represented by escape sequences which remove any such meaning.

BUGS
Platform-specific parts of the code are designed to be optimised away by the compiler for reasons of efficiency. This is achieved at considerable expense in terms of readability.

COPYRIGHT
Copyright (c)2009 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.

SEE ALSO
perl(1), Net::DNS, RFC1035, RFC2181.