SYNOPSIS

  use Data::Validate::Domain qw(is_domain);

  # as a function
  my $test = is_domain($suspect);
  die "$test is not a domain" unless defined $test;

  or

  my $test = is_domain($suspect,\%options);
  die "$test is not a domain" unless defined $test;


  # or as an object
  my $v = Data::Validate::Domain->new(%options);

  my $test = $v->is_domain($suspect);
  die "$test is not a domain" unless defined $test;

DESCRIPTION

This module collects domain validation routines to make input validation, and untainting easier and more readable.

All functions return an untainted value if the test passes, and undef if it fails. This means that you should always check for a defined status explicitly. Don't assume the return will be true. (e.g. is_username('0'))

The value to test is always the first (and often only) argument.

FUNCTIONS

new - constructor for \s-1OO\s0 usage

$obj = Data::Validate::Domain->new(); my %options = ( domain_allow_underscore => 1, );

or

my %options = ( domain_allow_single_label => 1, domain_private_tld => { 'privatetld1 ' => 1, 'privatetld2' => 1, } );

or

my %options = ( domain_allow_single_label => 1, domain_private_tld => qr /^(?:privatetld1|privatetld2)$/, );

$obj = Data::Validate::Domain->new(%options);

Description

Returns a Data::Validator::Domain object. This lets you access all the validator function calls as methods without importing them into your namespace or using the clumsy Data::Validate::Domain::function_name() format.

Options
domain_allow_underscore

According to \s-1RFC\s0 underscores are forbidden in \*(L"hostnames\*(R" but not \*(L"domainnames\*(R". By default is_domain,is_domain_label, and is_hostname will fail if you include underscores, setting this to a true value with authorize the use of underscores in all functions.

domain_allow_single_label

By default is_domain will fail if you ask it to verify a domain that only has a single label i.e. 'neely.cx' is good, but 'com' would fail. If you set this option to a true value then is_domain will allow single label domains through. This is most likely to be useful in combination with domain_private_tld

domain_private_tld

By default is_domain requires all domains to have a valid \s-1TLD\s0 (i.e. com, net, org, uk, etc), this is verified using the Net::Domain::TLD module. This behavior can be extended in two different ways. Either a hash reference can be supplied keyed by the additional \s-1TLD\s0's, or you can supply a precompiled regular expression. \s-1NOTE:\s0 The \s-1TLD\s0 is normalized to the lower case form prior to the check being done. This is done only for the \s-1TLD\s0 check, and does not alter the output in any way. The hash reference example:

domain_private_tld => { 'privatetld1 ' => 1, 'privatetld2' => 1, }

The precompiled regualar expression example:

domain_private_tld => qr /^(?:privatetld1|privatetld2)$/,

Returns

Returns a Data::Validate::Domain object

is_domain - does the value look like a domain name?

is_domain($value); or $obj->is_domain($value); or is_domain($value,\%options); or $obj->is_domain($value,\%options);

Description

Returns the untainted domain name if the test value appears to be a well-formed domain name. Note: See new for list of options and how those alter the behavior of this funciton.

Arguments

The potential domain to test.

Returns

Returns the untainted domain on success, undef on failure.

Notes, Exceptions, & Bugs

The function does not make any attempt to check whether a domain actually exists. It only looks to see that the format is appropriate. A dotted quad (such as 127.0.0.1) is not considered a domain and will return false. See Data::Validate::IP\|(3) for \s-1IP\s0 Validation. Performs a lookup via Net::Domain::TLD to verify that the \s-1TLD\s0 is valid for this domain. Does not consider \*(L"domain.com.\*(R" a valid format.

From \s-1RFC\s0 952

A "name" (Net, Host, Gateway, or Domain name) is a text string up to 24 characters drawn from the alphabet (A-Z), digits (0-9), minus sign (-), and period (.). Note that periods are only allowed when they serve to delimit components of "domain style names".

No blank or space characters are permitted as part of a name. No distinction is made between upper and lower case. The first character must be an alpha character [Relaxed in RFC 1123] . The last character must not be a minus sign or period.

From \s-1RFC\s0 1035

labels 63 octets or less names 255 octets or less

[snip] limit the label to 63 octets or less.

To simplify implementations, the total length of a domain name (i.e., label octets and label length octets) is restricted to 255 octets or less.

From \s-1RFC\s0 1123

One aspect of host name syntax is hereby changed: the restriction on the first character is relaxed to allow either a letter or a digit. Host software MUST support this more liberal syntax.

Host software MUST handle host names of up to 63 characters and SHOULD handle host names of up to 255 characters.

is_hostname - does the value look like a hostname

is_hostname($value); or $obj->is_hostname($value); or is_hostname($value,\%options); or $obj->is_hostname($value,\%options);

Description

Returns the untainted hostname if the test value appears to be a well-formed hostname. Note: See new for list of options and how those alter the behavior of this funciton.

Arguments

The potential hostname to test.

Returns

Returns the untainted hostname on success, undef on failure.

Notes, Exceptions, & Bugs

The function does not make any attempt to check whether a hostname actually exists. It only looks to see that the format is appropriate. Functions much like is_domain, except that it does not verify whether or not a valid \s-1TLD\s0 has been supplied and allows for there to only be a single component of the hostname (i.e www) Hostnames might or might not have a valid \s-1TLD\s0 attached.

is_domain_label - does the value look like a domain label?

is_domain_label($value); or $obj->is_domain_label($value); or is_domain_label($value,\%options); or $obj->is_domain_label($value,\%options);

Description

Returns the untainted domain label if the test value appears to be a well-formed domain label. Note: See new for list of options and how those alter the behavior of this funciton.

Arguments

The potential ip to test.

Returns

Returns the untainted domain label on success, undef on failure.

Notes, Exceptions, & Bugs

The function does not make any attempt to check whether a domain label actually exists. It only looks to see that the format is appropriate.

RELATED TO Data::Validate::Domain…

[\s-1RFC\s0 1034] [\s-1RFC\s0 1035] [\s-1RFC\s0 2181] [\s-1RFC\s0 1123]

Data::Validate\|(3)
Data::Validate::IP\|(3)

AUTHOR

Neil Neely <[email protected]>.

ACKNOWLEDGEMENTS

Thanks to Richard Sonnen <[email protected]> for writing the Data::Validate module.

Thanks to Len Reed <[email protected]> for helping develop the options mechanism for Data::Validate modules.

COPYRIGHT AND LICENSE

Copyright (c) 2005-2007 Neil Neely.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.2 or, at your option, any later version of Perl 5 you may have available.