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('/\bweiß\b/iu', 'weiss', 'weißbier'));
I would like the last regex to replace only full words and not parts of words.
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)
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"
Thus, the regex works as I expected on windows but not on linux.
So the main question is, how should I write my regex to only match at word boundaries?
A secondary questions is how I can let windows know that I want to use utf-8 in my php application.
Even in UTF-8 mode, standard class shorthands like \\w
and \\b
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
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.
Guess this was related to Bug #52971
PCRE-Meta-Characters like
\\b
\\w
not working with unicode strings.
PCRE extension: Fixed bug #52971 ( PCRE-Meta-Characters not working with utf-8 ).
here is what I have found so far. By rewriting the search and replacement patterns like this:
$before = '(^|[^\p{L}])';
$after = '([^\p{L}]|$)';
var_dump(preg_replace('/'.$before.'weiß'.$after.'/iu', '$1weiss$2', 'weißbier'));
// Test some other cases:
var_dump(preg_replace('/'.$before.'weiß'.$after.'/iu', '$1weiss$2', 'weiß'));
var_dump(preg_replace('/'.$before.'weiß'.$after.'/iu', '$1weiss$2', 'weiß bier'));
var_dump(preg_replace('/'.$before.'weiß'.$after.'/iu', '$1weiss$2', ' weiß'));
I get the wanted result:
string 'weißbier' (length=9)
string 'weiss' (length=5)
string 'weiss bier' (length=10)
string ' weiss' (length=6)
on both my windows computer running apache and on the hosted linux webserver running apache.
I assume there is some better way to do this.
Also, I still would like to setlocale my windows computer to utf-8.
According to this comment , that is a bug in PHP. Does using \\W
instead of \\b
give any benefit?
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