NAME
Net::IDN::Encode - Internationalizing Domain Names in Applications (IDNA)
SYNOPSIS
use Net::IDN::Encode ':all';
my $a = domain_to_ascii("müller.example.org");
my $e = email_to_ascii("POSTMASTER@例。テスト");
my $u = domain_to_unicode('EXAMPLE.XN--11B5BS3A9AJ6G');
DESCRIPTION
This module provides an easy-to-use interface for encoding and decoding Internationalized Domain Names (IDNs).
IDNs use characters drawn from a large repertoire (Unicode), but IDNA allows the non-ASCII characters to be represented using only the ASCII characters already allowed in so-called host names today (letter-digit-hypen, /[A-Z0-9-]/i
).
Use this module if you just want to convert domain names (or email addresses), using whatever IDNA standard is the best choice at the moment.
FUNCTIONS
By default, this module does not export any subroutines. You may use the :all
tag to import everything. You can also use regular expressions such as /^to_/
or /^email_/
to select some of the functions, see Exporter for details.
The following functions are available:
- to_ascii( $label, %param )
-
Converts a single label
$label
to ASCII. Will throw an exception on invalid input. If$label
is already a valid ASCII domain label (including most NON-LDH labels such as those used for SRV records and fake A-labels), this function will never fail but return$label
as-is if conversion would fail.This function takes the following optional parameters (
%param
):- AllowUnassigned
-
(boolean) If set to a true value, unassigned code points in the label are allowed. While maximizing the compatibility with future versions of Unicode and/or IDNA, this option is also dangerous: Characters added in future versions of Unicode might have properties that affect the conversion; you might therefore end up with a conversion that is incompatible with later standards. Therefore, set this to false unless you know what you are doing.
The default is false.
- UseSTD3ASCIIRules
-
(boolean) If set to a true value, checks the label for compliance with STD 3 (RFC 1123) syntax for host name parts. The exact checks done depend on the IDNA standard used. Usually, you will want to set this to true.
Please note that UseSTD3ASCIIRules only affects the conversion between ASCII labels (A-labels) and Unicode labels (U-labels). Labels that are in ASCII may still be passed-through as-is.
For historical reasons, the default is false (unlike
domain_to_ascii
). - TransitionalProcessing
-
(boolean) If set to true, the conversion will be compatible with IDNA2003. This only affects four characters:
'ß'
(U+00DF), 'ς' (U+03C2), ZWJ (U+200D) and ZWNJ (U+200C). Usually, you will want to set this to false.The default is false.
This function does not handle strings that consist of multiple labels (such as domain names). Use
domain_to_ascii
instead. - to_unicode( $label, %param )
-
Converts a single label
$label
to Unicode. Will throw an exception on invalid input. If$label
is an ASCII label (including most NON-LDH labels such as those used for SRV records), this function will not fail but return$label
as-is if conversion would fail.This function takes the same optional parameters as
to_ascii
, with the same defaults.If
$label
is already in ASCII, this function will never fail but return$label
as is as a last resort (i.e. pass-through).This function takes the following optional parameters (
%param
):- AllowUnassigned
- UseSTD3ASCIIRules
-
See
to_unicode
above. Please note that there is noTransitionalProcessing
forto_unicode
.
This function does not handle strings that consist of multiple labels (such as domain names). Use
domain_to_unicode
instead. - domain_to_ascii( $label, %param )
-
Converts all labels of the hostname
$domain
(with labels separated by dots) to ASCII (usingto_ascii
). Will throw an exception on invalid input.This function takes the following optional parameters (
%param
):- AllowUnassigned
- TransitionalProcessing
-
See
to_unicode
above. - UseSTD3ASCIIRules
-
(boolean) If set to a true value, checks the label for compliance with STD 3 (RFC 1123) syntax for host name parts.
The default is true (unlike
to_ascii
).
This function will convert all dots to ASCII, i.e. to U+002E (full stop). The following characters are recognized as dots: U+002E (full stop), U+3002 (ideographic full stop), U+FF0E (fullwidth full stop), U+FF61 (halfwidth ideographic full stop).
- domain_to_unicode( $domain, %param )
-
Converts all labels of the hostname
$domain
(with labels separated by dots) to Unicode. Will throw an exception on invalid input.This function takes the same optional parameters as
domain_to_ascii
, with the same defaults.This function takes the following optional parameters (
%param
):- AllowUnassigned
- UseSTD3ASCIIRules
-
See
domain_to_unicode
above. Please note that there is noTransitionalProcessing
fordomain_to_unicode
.
This function will preserve the original version of dots. The following characters are recognized as dots: U+002E (full stop), U+3002 (ideographic full stop), U+FF0E (fullwidth full stop), U+FF61 (halfwidth ideographic full stop).
- email_to_ascii( $email, %param )
-
Converts the domain part (right hand side, separated by an at sign) of an RFC 2821/2822 email address to ASCII, using
domain_to_ascii
. May throw an exception on invalid input.It takes the same parameters as
domain_to_ascii
.This function currently does not handle internationalization of the local-part (left hand side). Future versions of this module might implement an ASCII conversion for the local-part, should one be standardized.
This function will convert the at sign to ASCII, i.e. to U+0040 (commercial at), as well as label separators. The follwing characters are recognized as at signs: U+0040 (commercial at), U+FF20 (fullwidth commercial at).
- email_to_unicode( $email, %param )
-
Converts the domain part (right hand side, separated by an at sign) of an RFC 2821/2822 email address to Unicode, using
domain_to_unicode
. May throw an exception on invalid input.It takes the same parameters as
domain_to_unicode
.This function currently does not handle internationalization of the local-part (left hand side). Future versions of this module might implement a conversion from ASCII for the local-part, should one be standardized.
This function will preserve the original version of at signs (and label separators). The follwing characters are recognized as at signs: U+0040 (commercial at), U+FF20 (fullwidth commercial at).
AUTHOR
Claus Färber <CFAERBER@cpan.org>
LICENSE
Copyright 2007-2012 Claus Färber.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
SEE ALSO
Net::IDN::Punycode, Net::IDN::UTS46, Net::IDN::IDNA2003, Net::IDN::IDNA2008, UTS #46 (http://www.unicode.org/reports/tr46/), RFC 5890 (http://tools.ietf.org/html/rfc5890).