3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $str = 'a,b\,c,d'; var_dump(preg_split('/(?<!(?!\x5c).[\x5c]),/', $str));
based on r0BbG
Output for 4.3.0 - 7.1.0
array(3) { [0]=> string(1) "a" [1]=> string(4) "b\,c" [2]=> string(1) "d" }