- preg_replace: documentation ( source)
<?php
$output = "Clean :this; [c<op=y of i>nv\al?id@ non AS]CII äóchar^acters.";
$output = preg_replace('/[\x00-\x1F]|[\x21-\x2C]|[\x3A-\x40]|[\x5B-\x5E]|[\x7B-\x7D]|[\x80-\xBF]|[\x2B0-\x36F]|[\x2000-\x3BFF]|/','', $output);
echo($output);