How to do regular expression substitution?

Question

PHP

Hello.
I need to do a regular expression replacement, I do it like this:

preg_replace('/{{(.+)}}/', substr('$1', 0, -5), $text);

The second parameter replacement can contain references of the form $n (any number instead of n). Each such link will be replaced with a substring corresponding to the nth subpattern.
But the problem is that when calling the substr(); this link is not substituted into the first parameter, but I need to do it. That is, I need a substring corresponding to this mask (.+) to be passed to the substr function as the first parameter.
Tell me how can I do this?

Answer 1

$text = preg_replace_callback('/{{(.+)}}/', function ($value) {
    return substr($value[1], 0, -5);
}, $text);