---
name: "MDN::API"
section: "3pm"
platform: "linux"
package: "libmdn-perl"
version: "2.4-2"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/MDN::API"
---

# MDN::API(3pm)

Perl interface to domain name conversion methods of libmdn

## NAME

MDN::API - Perl interface to domain name conversion methods of libmdn

## SYNOPSIS

```
  use MDN::API;
```

```
  $idn_domain_name = MDN::API->encode_name($local_domain_name);
  $local_domain_name = MDN::API->decode_name($idn_domain_name);
```

## DESCRIPTION

`"MDN::API"` provides a Perl object interface to domain name conversion methods of libmdn, the multilingual domain name library included in the mDNkit.

This module provides high-level conversion interface to the library. It can encode or decode a domain name according with libmdn configuration (e.g. `"/usr/local/etc/mdn.conf"`).

## CLASS METHODS

Although this module does not provide object interface, all the functions should be called as class methods, in order to be consistent with other modules in `"MDN::"`.

```
        MDN::API->encode_name($domain_name);  # OK
        MDN::API::encode_name($domain_name);  # NG
```

- encode\_name($from \[, @actions...\])

  Encodes domain name of `$from` according with `@actions`, and returns the result.

  Each element in `@actions` is a string as follows:

  ```
      'localconv'     convert the local encoding string to UTF-8.
      'delimmap'      covnert local delimiters to periods ('.').
      'localmap'      perfrom local mapping.
      'nameprep'      perform NAMEPREP (mapping, normalization,
                      prohibit character check and unassigned
                      codepoint check).
      'idnconv'       convert the UTF-8 string to ACE.
  ```

  ```
      'encode_app'    perform 'localconv', 'delimmap', 'localmap',
                      'nameprep' and 'idnconv'.  This is the default
                      value of @actions.
  ```

  Regardless of the order of elements in `@actions`, the actions are always performed in the following order; `'localconv'`, `'delimmap'`, `'localmap'`, `'nameprep'` and `'idnconv'`.

  If an error occurs, this method returns `"undef"`.

- decode\_name($from \[, @actions...\])

  Decodes domain name of `$from` according with `@actions`, and returns the result.  This is the reverse of `"encode_name"`.

  Each element in `@actions` is a string as follows:

  ```
      'idnconv'       convert the ACE string to UTF-8.
      'nameprep'      inspect if NAMEPREP has been performed to the
                      string.  If hasn't, convert the string to ACE.
      'localconv'     convert the UTF-8 string to the local encoding.
  ```

  ```
      'decode_app'    perform 'idnconv', 'nameprep' and 'localconv'.
                      This is the default value of @actions.
  ```

  Regardless of the order of elements in `@actions`, those actions are always performed in the following order; `'idnconv'`, `'nameprep'` and `'localconv'`.

  If an error occurs, this method returns `"undef"`.

- enable($on\_off)

  Enable or disable mulitilingual domain name support provided by libmdn. If `$on_off` is zero, the support is disabled, otherwise enabled. If this method has not been called, the `"MDN_DISABLE"` environment variabe is used to determine whether mulitilingual domain name support is enabled. The support is disabled if that variable is defined,

  In disabled condition, conversion methods (e.g. `"encode_name()"` and `"decode_name()"`) simply return a copy of input string as the result of conversion.

- *lasterror()*

  Returns the error message string corresponding to the last error occurred in this module.

- local\_to\_utf8($from)

  Is equivalent to `"encode_name($from, 'localconv')"`.

- utf8\_to\_local($from)

  Is equivalent to `"decode_name($from, 'localconv')"`.

- delimiter\_map($from)

  Is equivalent to `"encode_name($from, 'delimmap')"`.

- local\_map($from)

  Is equivalent to `"encode_name($from, 'localmap')"`.

- nameprep($from)

  Is equivalent to `"encode_name($from, 'nameprep')"`.

- nameprep\_check($from)

  Is equivalent to `"decode_name($from, 'nameprep')"`.

- utf8\_to\_idn($from)

  Is equivalent to `"encode_name($from, 'idnconv')"`.

- idn\_to\_utf8($from)

  Is equivalent to `"decode_name($from, 'idnconv')"`.

- local\_to\_idn($from)

  Is equivalent to `"encode_name($from)"`.

- idn\_to\_local($from)

  Is equivalent to `"decode_name($from)"`.

## COMPATIBILITY

Beginning with version 2.4, the action `'nameprep'` of `"encode_name()"` and `"decode_name()"` also performs unassigned codepoint check. The `'unascheck'` action and the `"unassigned_check()"` method are no longer supported.

## ISSUE OF HANDLING UNICODE CHARACTERS

See the \`\`ISSUE OF HANDLING UNICODE CHARACTERS'' section in MDN::UTF8.

## SEE ALSO

[*mdn.conf*(5)](/mdn.conf/5.md), MDN::ResConf, MDN::UTF8

MDN library specification