idn_to_ascii

(PHP 5 >= 5.3.0, PHP 7, PECL intl >= 1.0.2, PECL idn >= 0.1)

idn_to_ascii — Convert domain name to IDNA ASCII form

说明

过程化风格

idn_to_ascii ( string $domain [, int $options = IDNA_DEFAULT [, int $variant = INTL_IDNA_VARIANT_UTS46 [, array &$idna_info ]]] ) : string

This function converts a Unicode domain name to an IDNA ASCII-compatible format.

参数

domain: The domain to convert, which must be UTF-8 encoded.
options: Conversion options - combination of IDNA_* constants (except IDNA_ERROR_* constants).
variant: Either INTL_IDNA_VARIANT_2003 for IDNA 2003 or INTL_IDNA_VARIANT_UTS46 for UTS #46.
idna_info: This parameter can be used only if INTL_IDNA_VARIANT_UTS46 was used for variant. In that case, it will be filled with an array with the keys 'result', the possibly illegal result of the transformation, 'isTransitionalDifferent', a boolean indicating whether the usage of the transitional mechanisms of UTS #46 either has or would have changed the result and 'errors', which is an int representing a bitset of the error constants IDNA_ERROR_*.

返回值

The domain name encoded in ASCII-compatible form, 或者在失败时返回 FALSE

更新日志

版本	说明
7.4.0	The default value of `variant` is now `INTL_IDNA_VARIANT_UTS46` instead of the deprecated `INTL_IDNA_VARIANT_2003`.
7.2.0	`INTL_IDNA_VARIANT_2003` has been deprecated; use `INTL_IDNA_VARIANT_UTS46` instead.
5.4.0/PECL 2.0.0b1	Added the parameters `variant` and `idna_info`; UTS #46 support (requires ICU ≥ 4.6).

范例

Example #1 idn_to_ascii() example


<?php

echo idn_to_ascii('t?st.de'); 

?>

以上例程会输出：

xn--tst-qla.de

参见

idn_to_utf8() - Convert domain name from IDNA ASCII to Unicode

User Contributed Notes

mschrieck at gmail dot com 31-Mar-2017 01:03


To convert IDN Domains with the IDNA2008 definition use following command.



idn_to_ascii('te?t.com',IDNA_NONTRANSITIONAL_TO_ASCII,INTL_IDNA_VARIANT_UTS46)



The result is then as expected



xn--tet-6ka.com

edible dot email at gmail dot com 03-Jun-2012 05:08


The notes on this function are not very clear and a little misleading.





Firstly, <=5.3, you will need to make use of one of several scripts or classes available on the internet which might, or might not, require the installation of of the intl and idn PECL extensions ...and you will need to have !<4.0 in order to be able to install both.





Secondly, if you have >=5.4 you will not require the PECL extensions.





Third, use of utf8_encode() is not necessary.  In fact, it will potentially prevent idn_to_ascii() from working at all.





On my setup it was necessary to change the charset in the script meta tags to UTF-8:





<meta http-equiv="Content-Type" content="text/html; CHARSET=gb2312" />





...and to change charset_default in the php.ini file (/usr/local/lib/php.ini, whereis php.ini, find / -name php.ini):





default_charset = "UTF-8"





The above changes mean that idn_to_ascii() can now be used with that syntax (no need for utf8_encode()).  Previously, the function worked to convert some IDNs, but failed to convert Japanese and Cyrillic IDNs.  Further, no additional locales were enabled or added, and Apache's charset file was left unmodified.





It is also important to remember only to apply the function where required, eg:





idn_to_ascii(c?sino.com) // is wrong





...whereas...





iden_to_ascii(c?sino) // is right





...and also be aware of text editors that don't support UTF-8 encoding, or the $domain = 'c?sino' value will end up as $domain = '??????' ...and the function will fail.





I have found that Notepad++ easily and reliably handles UTF-8 encoding that works for this function using UTF-8 as the encoding option, not UTF-8 without BOM.