utf-8中的php正则表达式单词边界匹配 [英] php regex word boundary matching in utf-8

问题描述

我在 utf-8 php 文件中有以下 php 代码:

I have the following php code in a utf-8 php file:

var_dump(setlocale(LC_CTYPE, 'de_DE.utf8', 'German_Germany.utf-8', 'de_DE', 'german'));
var_dump(mb_internal_encoding());
var_dump(mb_internal_encoding('utf-8'));
var_dump(mb_internal_encoding());
var_dump(mb_regex_encoding());
var_dump(mb_regex_encoding('utf-8'));
var_dump(mb_regex_encoding());
var_dump(preg_replace('/weiß/iu', 'weiss', 'weißbier'));

我希望最后一个正则表达式只替换完整的单词而不是部分单词.

I would like the last regex to replace only full words and not parts of words.

在我的 Windows 计算机上，它返回:

On my windows computer, it returns:

string 'German_Germany.1252' (length=19)
string 'ISO-8859-1' (length=10)
boolean true
string 'UTF-8' (length=5)
string 'EUC-JP' (length=6)
boolean true
string 'UTF-8' (length=5)
string 'weißbier' (length=9)

在网络服务器 (linux) 上，我得到:

On the webserver (linux), I get:

string(10) "de_DE.utf8"
string(10) "ISO-8859-1"
bool(true)
string(5) "UTF-8"
string(10) "ISO-8859-1"
bool(true)
string(5) "UTF-8"
string(9) "weissbier"

因此，正则表达式在 Windows 上按我的预期工作，但在 linux 上却没有.

Thus, the regex works as I expected on windows but not on linux.

所以主要问题是，我应该如何编写我的正则表达式以仅匹配单词边界?

So the main question is, how should I write my regex to only match at word boundaries?

第二个问题是如何让 windows 知道我想在我的 php 应用程序中使用 utf-8.

A secondary questions is how I can let windows know that I want to use utf-8 in my php application.

推荐答案

即使在 UTF-8 模式下，像 w 和  这样的标准类简写也不是 Unicode-知道的.您只需要使用 Unicode 速记，正如您所研究的那样，但是您可以通过使用环顾而不是交替来使它不那么难看:

Even in UTF-8 mode, standard class shorthands like w and  are not Unicode-aware. You just have to use the Unicode shorthands, as you worked out, but you can make it a little less ugly by using lookarounds instead of alternations:

/(?<!pL)weiß(?!pL)/u

还要注意我是如何将花括号从 Unicode 类速记中去掉的；当类名由单个字母组成时，您可以这样做.

Notice also how I left the curly braces out of the Unicode class shorthands; you can do that when the class name consists of a single letter.

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