php - How to match Japanese regular expression with u flag? - php

Question

Something weird is happening with preg_match when I feed it the following strings. I am using the 'u' flag because I am trying to match a mixed Japanese string.
<?php
$subject="/hello/カメラ/";
$pattern='#^/hello/([\p{Han}\p{Katakana}\p{Hiragana}\w\-]+)/#u';
$result=preg_match($pattern,$subject);
echo $result; // 1
$subject="/hello/カレンダー/";
$pattern='#^/hello/([\p{Han}\p{Katakana}\p{Hiragana}\w\-]+)/#u';
$result=preg_match($pattern,$subject);
echo $result; // 0
?>
Notice that both $pattern variables have the same construction '/hello/katakana/'. Then, why is the first $result 1 and the second one 0?
Is that a bug?
Update:
I am running PHP Version 5.5.24 on a Mac.

Answer 1

Many thanks to David Vartanian for his help.
To make the regular expression work for both cases, I had to update the pattern the following way.
$pattern='#^/hello/([\x{30A0}-\x{30FF}\x{3040}-\x{309F}\x{4E00}-\x{9FBF}\w\-]+)/#u';
However, it seems like the older pattern works on PHP 5.5.9 and newer as mentioned by chris.

Answer 2

You could use mb_ereg_match(), this function is especially for multibyte regex, do no confuse with ereg_* deprecated. To use it just remove the delimiters and the modifier u.
<?php
$subject="/hello/カメラ/";
$pattern='^/hello/([\p{Han}\p{Katakana}\p{Hiragana}\w\-]+)/';
$result = mb_ereg_match($pattern, $subject);
echo "<pre>";
print_r($result);
$subject="/hello/カレンダー/";
$pattern='^/hello/([\p{Han}\p{Katakana}\p{Hiragana}\w\-]+)/';
$result = mb_ereg_match($pattern, $subject);
print_r($result);