--TEST-- preg_replace() with array of failing regular expressions --INI-- pcre.backtrack_limit=100000 --FILE-- <?php $text = '[CODE]<td align="$stylevar[right]">[/CODE]'; $result = preg_replace(array('#\[(right)\](((?R)|[^[]+?|\[)*)\[/\\1\]#siU', '#\[(right)\](((?R)|[^[]+?|\[)*)\[/\\1\]#siU'), '', $text); var_dump($text); var_dump($result); $result = preg_replace('#\[(right)\](((?R)|[^[]+?|\[)*)\[/\\1\]#siU', '', $text); var_dump($text); var_dump($result); echo "Done\n"; ?> --EXPECTF-- string(58) "[CODE]<td align="$stylevar[right]">[/CODE]" NULL string(58) "[CODE]<td align="$stylevar[right]">[/CODE]" NULL Done