mb_regex_encoding

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

mb_regex_encoding — Set/Get character encoding for multibyte regex

说明

mb_regex_encoding ( string|null $encoding = null ) : string|bool

Set/Get character encoding for a multibyte regex.

参数

encoding: encoding 参数为字符编码。如果省略或是 null，则使用内部字符编码。

返回值

If encoding is set, then 成功时返回 true，或者在失败时返回 false。 In this case, the internal character encoding is NOT changed. If encoding is omitted, then the current character encoding name for a multibyte regex is returned.

更新日志

版本	说明
8.0.0	现在 `encoding` 可以为 null。

参见

mb_internal_encoding() - 设置/获取内部字符编码
mb_ereg() - Regular expression match with multibyte support

User Contributed Notes

GerryH 16-Sep-2017 01:49


mb_ereg functionality is provided via Oniguruma RegEx library and not via PCRE. mb_regex_encoding() does only support a subset of encoding names, compared to mb_list_encodings() and mb_encoding_aliases().

Currently the following names are supported (case-insensitive):



UCS-4

UCS-4LE

UTF-32

UTF-32BE

UTF-32LE

UTF-16

UTF-16BE

UTF-16LE

UTF-8

utf8

ASCII

US-ASCII

EUC-JP

eucJP

x-euc-jp

SJIS

eucJP-win

SJIS-win

CP932

MS932

Windows-31J

ISO-8859-1

ISO-8859-2

ISO-8859-3

ISO-8859-4

ISO-8859-5

ISO-8859-6

ISO-8859-7

ISO-8859-8

ISO-8859-9

ISO-8859-10

ISO-8859-13

ISO-8859-14

ISO-8859-15

ISO-8859-16

EUC-CN

EUC_CN

eucCN

gb2312

EUC-TW

EUC_TW

eucTW

BIG-5

CN-BIG5

BIG-FIVE

BIGFIVE

EUC-KR

EUC_KR

eucKR

KOI8-R

KOI8R



The list is a mixture of base names and aliases and applies to PHP 5.4.45 (Oniguruma lib v4.7.1), PHP 5.6.31 (v5.9.5), PHP 7.0.22 (v5.9.6) and PHP 7.1.8 (v5.9.6). Be aware of the inconsistency: mb_regex_encoding() accepts for example the base name 'UTF-8' and its only alias 'utf8', but it does not accept aliases 'utf16', 'utf32' or 'latin1'.



Additionally note, that the informal name/alias 'latin9' for ISO/IEC 8859-15:1999 (including the Euro sign on 0xA4) is also not known by mb_list_encodings(). It can only be adressed as 'ISO-8859-15' or 'ISO_8859-15' and for mb_regex_encoding() solely as 'ISO-8859-15'.

code at roberthairgrove dot com 03-Aug-2017 10:19


mb_regex_encoding does not recognize CP1252 or Windows-1252 as valid encodings, although they are in the list generated by mb_list_encodings.



ISO-8859-1 (AKA "Latin-1") is supported, but it's not the same as the Windows variety of Latin-1.

php dot net at phor dot net 31-Aug-2010 01:40


Beware, mb_regex_encoding does not support the same set of encodings as listed in mb_list_encodings.php



Example:



<?php

mb_internal_encoding('CP936');

mb_regex_encoding('CP936'); # this line produces an error

 ?>

Anonymous 28-Jun-2009 10:07


To change algo the regex_encodign

<?php

echo "current mb_internal_encoding: ".mb_internal_encoding()."<br />";

echo "changing mb_internal_encoding to UTF-8<br />";

mb_internal_encoding("UTF-8"); 

echo "new mb_internal_encoding: ".mb_internal_encoding()."<br />";



echo "current mb_regex_encoding: ".mb_regex_encoding()."<br />";

echo "changing mb_regex_encoding to UTF-8<br />";

mb_regex_encoding('UTF-8');

echo "new mb_regex_encoding: ".mb_regex_encoding()."<br />";

?>

zl at zl dot hu 29-May-2009 06:05


Return values vary in setting and getting:



<?php

  echo mb_regex_encoding();

  // returns encoding name as a string

?>



<?php

  echo mb_regex_encoding("UTF-8");

  // returns true (success) of false as a boolean

?>