Stripos in the MIGX extension filter - how to make it work correctly with Cyrillic?

Question

PHP

Good day! I'm picking the MIGX extension - its filter. I need to display records where a keyword occurs - case insensitive. The code snippet in the extension is responsible for this:

case 'contains':
      $output = strpos($subject, $operand) !== false ? $then : (isset($else) ? $else : '');
break;

I reduced everything even to lower case, I use stripos instead of strpos:

case 'contains':
  $subject = strtolower($subject);
  $operand = strtolower($operand);
        $output = stripos($subject, $operand) !== false ? $then : (isset($else) ? $else : '');
break;

But it doesn't want to work point-blank... With Latin characters, the case is not important, but in Russian words it does not find an occurrence... CHAYDNT?

Answer 1

Guys, it was all about php version. It was 5.3, changed to 5.6 and began to work. Or it was necessary to prescribe the data encoding.

Answer 2

This seems to be normal behavior for unicode.
Try strpos first by making it smaller.
There is also mb_strpos.