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Data::Validate::DomainUser)Contributed Perl DocumenData::Validate::Domain(3pm)

NAME
       Data::Validate::Domain - domain validation methods

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 OO 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 RFC underscores are forbidden in "hostnames"
                   but not "domainnames".  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
                   TLD (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 TLD's, or you can supply a
                   precompiled regular expression.

                   NOTE:  The TLD is normalized to the lower case form prior
                   to the check being done.  This is done only for the TLD
                   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
               $value
                   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 IP
               Validation.

               Performs a lookup via Net::Domain::TLD to verify that the TLD
               is valid for this domain.

               Does not consider "domain.com." a valid format.

           From RFC 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 RFC 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 RFC 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
               $value
                   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 TLD 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 TLD 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
               $value
                   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.

SEE ALSO
       [RFC 1034] [RFC 1035] [RFC 2181] [RFC 1123]

       Data::Validate(3)
       Data::Validate::IP(3)

AUTHOR
       Neil Neely <neil@neely.cx>.

ACKNOWLEDGEMENTS
       Thanks to Richard Sonnen <sonnen@richardsonnen.com> for writing the
       Data::Validate module.

       Thanks to Len Reed <lreed@levanta.com> 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.

perl v5.32.0                      2020-12-27       Data::Validate::Domain(3pm)

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