Net::LibIDN2(3pm)

💖 Net::LibIDN2(3pm) 💖

okay so bestie, welcome to the User Contributed Perl Documentation page for Net::LibIDN2(3pm) — the Perl bindings for GNU Libidn2, a C library that handles internationalized domain names using IDNA 2008, Punycode and TR46. This is the whole manual, every flag and every error code, no skips, no cap. 💅

✨ NAME ✨

Net::LibIDN2 — Perl bindings for GNU Libidn2.

🌸 SYNOPSIS 🌸

okay so here's the vibe check in code form:

use Net::LibIDN2 ':all';
use Encode;

idn2_lookup_u8(Encode::encode_utf8("m\N{U+00FC}\N{U+00DF}li.de"))
  eq 'xn--mli-5ka8l.de';

idn2_register_u8(
  Encode::encode_utf8("m\N{U+00FC}\N{U+00DF}li"),
  "xn--mli-5ka8l"
) eq 'xn--mli-5ka8l';

Encode::decode_utf8(idn2_to_unicode_88("xn--mli-5ka8l.de"))
  eq "m\N{U+00FC}\N{U+00DF}li.de"

🦋 DESCRIPTION 🦋

Provides bindings for GNU Libidn2, a C library for handling internationalized domain names based on IDNA 2008, Punycode and TR46.

💅 Functions 💅

Net::LibIDN2::idn2_lookup_u8($src, [$flags, [$rc]]);

Alternative name idn2_to_ascii_8.

This one does IDNA2008 lookup string conversion on the domain name $src, exactly as described in section 5 of RFC 5891. Note that the input string must be encoded in UTF-8 and be in Unicode NFC form.

Pass IDN2_NFC_INPUT in $flags to convert the input to NFC form before further processing. IDN2_TRANSITIONAL and IDN2_NONTRANSITIONAL do already imply IDN2_NFC_INPUT.

Pass IDN2_ALABEL_ROUNDTRIP in $flags to convert any input A-labels to U-labels and perform additional testing. This is default if used with a libidn2 version >= 2.2. To switch this behavior off, pass IDN2_NO_ALABEL_ROUNDTRIP.

Pass IDN2_TRANSITIONAL to enable Unicode TR46 transitional processing, and IDN2_NONTRANSITIONAL to enable Unicode TR46 non-transitional processing.

Multiple flags may be specified by binary or:ing them together, for example IDN2_NFC_INPUT | IDN2_ALABEL_ROUNDTRIP.

heads up, bestie: if linked to library GNU Libidn2 version > 2.0.3, IDN2_USE_STD3_ASCII_RULES is disabled by default. Previously we were eliminating non-STD3 characters from domain strings such as _443._tcp.example.com, or IPs 1.2.3.4/24 provided to libidn2 functions. That was an unexpected regression for applications switching from libidn2 and thus it is no longer applied by default. Use IDN2_USE_STD3_ASCII_RULES to enable that behavior again.

On error, returns undef. If a scalar variable is provided in $rc, returns the internal libidn2 C library result code as well.

Net::LibIDN2::idn2_lookup_ul($src, [$flags, [$rc]]);

Alternative name idn2_to_ascii_l.

Similar to function idn2_lookup_u8 but $src is assumed to be encoded in the locale's default coding system, and will be transcoded to UTF-8 and NFC normalized before returning the result.

Net::LibIDN2::idn2_register_u8($ulabel, [$alabel, [$flags, [$rc]]]);

Perform IDNA2008 register string conversion on domain label $ulabel and $alabel, as described in section 4 of RFC 5891. Note that the input ulabel must be encoded in UTF-8 and be in Unicode NFC form.

Pass IDN2_NFC_INPUT in $flags to convert input $ulabel to NFC form before further processing.

It is recommended to supply both $ulabel and $alabel for better error checking, but supplying just one of them will work. Passing in only $alabel is better than only $ulabel. See RFC 5891 section 4 for more information.

On error, returns undef. If a scalar variable is provided in $rc, returns the internal libidn2 C library result code as well.

Net::LibIDN2::idn2_register_ul($ulabel, [$alabel, [$flags, [$rc]]]);

Similar to function idn2_register_u8 but $ulabel is assumed to be encoded in the locale's default coding system, and will be transcoded to UTF-8 and NFC normalized before returning the result.

Net::LibIDN2::idn2_to_unicode_88($input, [$flags, [$rc]]);

Converts a possibly ACE encoded domain name in UTF-8 format into an UTF-8 encoded string (punycode decoding).

On error, returns undef. If a scalar variable is provided in $rc, returns the internal libidn2 C library result code as well.

Net::LibIDN2::idn2_to_unicode_8l($input, [$flags, [$rc]]);

Similar to function idn2_to_unicode_88 but the return value is encoded in the locale's default coding system.

Net::LibIDN2::idn2_to_unicode_ll($input, [$flags, [$rc]]);

Similar to function idn2_to_unicode_8l but $input is also assumed to be encoded in the locale's default coding system.

Net::LibIDN2::idn2_strerror($rc);

Convert internal libidn2 error code $rc to a human-readable string.

Net::LibIDN2::idn2_strerror_name($rc);

Convert internal libidn2 error code $rc to a string corresponding to internal header file symbols names like IDN2_MALLOC.

Net::LibIDN2::idn2_check_version([$req_version])

Checks that the version of the underlying IDN2 C library is at minimum the one given as a string in $req_version and if that is the case returns the actual version string of the underlying C library or undef if the condition is not met. If no parameter is passed to this function no check is done and only the version string is returned.

See IDN2_VERSION for a suitable $req_version string, it corresponds to the idn2.h C header file version at compile time of this Perl module. Normally these two version numbers match, but if you compiled this Perl module against an older libidn2 and then run it with a newer libidn2 shared library, they will be different.

🎀 Constants 🎀

• IDN2_VERSION — Pre-processor symbol with a string that describes the C header file version number at compile time of this Perl module. Used together with idn2_check_version() to verify header file and run-time library consistency.
• IDN2_VERSION_NUMBER — Pre-processor symbol with a hexadecimal value describing the C header file version number at compile time of this Perl module. For example, when the header version is 1.2.4711 this symbol will have the value 0x01021267. The last four digits are used to enumerate development snapshots, but for all public releases they will be 0000.
• IDN2_VERSION_MAJOR — Pre-processor symbol for the major version number (decimal). The version scheme is major.minor.patchlevel.
• IDN2_VERSION_MINOR — Pre-processor symbol for the minor version number (decimal). The version scheme is major.minor.patchlevel.
• IDN2_VERSION_PATCH — Pre-processor symbol for the patch level number (decimal). The version scheme is major.minor.patchlevel.
• IDN2_LABEL_MAX_LENGTH — Constant specifying the maximum length of a DNS label to 63 characters, as specified in RFC 1034.
• IDN2_DOMAIN_MAX_LENGTH — Constant specifying the maximum size of the wire encoding of a DNS domain to 255 characters, as specified in RFC 1034. Note that the usual printed representation of a domain name is limited to 253 characters if it does not end with a period or 254 characters if it ends with a period.

🍓 Result codes 🍓

• Net::LibIDN2::IDN2_OK — Successful return.
• Net::LibIDN2::IDN2_MALLOC — Memory allocation error.
• Net::LibIDN2::IDN2_NO_CODESET — Could not determine locale string encoding format.
• Net::LibIDN2::IDN2_ICONV_FAIL — Could not transcode locale string to UTF-8.
• Net::LibIDN2::IDN2_ENCODING_ERROR — Unicode data encoding error.
• Net::LibIDN2::IDN2_NFC — Error normalizing string.
• Net::LibIDN2::IDN2_PUNYCODE_BAD_INPUT — Punycode invalid input.
• Net::LibIDN2::IDN2_PUNYCODE_BIG_OUTPUT — Punycode output buffer too small.
• Net::LibIDN2::IDN2_PUNYCODE_OVERFLOW — Punycode conversion would overflow.
• Net::LibIDN2::IDN2_TOO_BIG_DOMAIN — Domain name longer than 255 characters.
• Net::LibIDN2::IDN2_TOO_BIG_LABEL — Domain label longer than 63 characters.
• Net::LibIDN2::IDN2_INVALID_ALABEL — Input A-label is not valid.
• Net::LibIDN2::IDN2_UALABEL_MISMATCH — Input A-label and U-label does not match.
• Net::LibIDN2::IDN2_NOT_NFC — String is not NFC.
• Net::LibIDN2::IDN2_2HYPHEN — String has forbidden two hyphens.
• Net::LibIDN2::IDN2_HYPHEN_STARTEND — String has forbidden starting/ending hyphen.
• Net::LibIDN2::IDN2_LEADING_COMBINING — String has forbidden leading combining character.
• Net::LibIDN2::IDN2_DISALLOWED — String has disallowed character.
• Net::LibIDN2::IDN2_CONTEXTJ — String has forbidden context-j character.
• Net::LibIDN2::IDN2_CONTEXTJ_NO_RULE — String has context-j character with no rule.
• Net::LibIDN2::IDN2_CONTEXTO — String has forbidden context-o character.
• Net::LibIDN2::IDN2_CONTEXTO_NO_RULE — String has context-o character with no rule.
• Net::LibIDN2::IDN2_UNASSIGNED — String has forbidden unassigned character.
• Net::LibIDN2::IDN2_BIDI — String has forbidden bi-directional properties.
• Net::LibIDN2::IDN2_DOT_IN_LABEL — Label has forbidden dot (TR46).
• Net::LibIDN2::IDN2_INVALID_TRANSITIONAL — Label has character forbidden in transitional mode (TR46).
• Net::LibIDN2::IDN2_INVALID_NONTRANSITIONAL — Label has character forbidden in non-transitional mode (TR46).

👑 AUTHOR 👑

Thomas Jacob, https://github.com/gnuthor.

🌈 SEE ALSO 🌈

• perl(1)
• RFC 5890-5893
• TR 46
• https://gitlab.com/libidn/libidn2

🎀 that’s the whole page, bestie — source/version: perl v5.42.0, date: 2023-03-29, and yes this is the Net::LibIDN2(3pm) page. mwah 💋