模式适用于regex101，但不适用于服务器

Question

My pattern:

/{LOOP:(\w+)[^}]*}((\s*?.?)*?){\/LOOP:\1}/

My test string:

<tbody>
    {LOOP:MENU}
    <tr>
        <td>{VAR:ID}</td>
        <td>{VAR:NAME}</td>
        <td>{VAR:ROLLE}</td>
        <td>{VAR:ACTIONS}</td>
    </tr>
    {/LOOP:MENU}
</tbody>

When you try it on regex101 it is working without any problems. But when I try it on my Server with preg_match_all() it is not working. preg_last_error() returns:

2(PREG_BACKTRACK_LIMIT_ERROR).

How is that possible with regex101 telling me "1 Match in 581 Steps"? Or has the number of Steps nothing to do with Backtrack?

I'm using apache2 Server with PHP Version 5.5.9-1ubuntu4.16.

In my php.ini, pcre.backtrack_limit is set on 1000000.

EDIT:

Following the tip of Alan Moore, I now use the following pattern:

/{LOOP:(\w+)[^}]*}(.*?){\/LOOP:\1}/s

This gives back 0(NO_ERROR). But on my server it is now not matching anything. Why is it working on regex101 but not on my server?

PHP:

$test="<tbody>
        {LOOP:MENU}
        <tr>
            <td>{VAR:ID}</td>
            <td>{VAR:NAME}</td>
            <td>{VAR:ROLLE}</td>
            <td>{VAR:ACTIONS}</td>
        </tr>
        {/LOOP:MENU}
       </tbody>"
preg_match_all("/{LOOP:(\w+)[^}]*}(.*?){\/LOOP:\1}/s", $test, $matches, PREG_SET_ORDER);
// $matches is now an emty array.

Answer 1

php needs an extra backslash here and there in regexes. in this case, changing \1 to \\1 works:

preg_match_all("/{LOOP:(\w+)[^}]*}(.*){\/LOOP:(\\1)}/s", ...

alternatively, single backslash is ok here with single-quotes, and you can save some trouble by always using single quotes around regexes:

preg_match_all('/{LOOP:(\w+)[^}]*}(.*){\/LOOP:(\1)}/s', ...