3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $pattern = <<<REGEXP /(?(R) # in case of recursion match parentheses \(((?>[^\s()]+)|(?R))*\) | # else match a link with title ^\((((?>[^\s()]+)|(?R))*)(\s+"(.*?)")?\) )/x REGEXP; print $pattern;
Output for 4.3.0 - 5.6.28, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
/(?(R) # in case of recursion match parentheses \(((?>[^\s()]+)|(?R))*\) | # else match a link with title ^\((((?>[^\s()]+)|(?R))*)(\s+"(.*?)")?\) )/x