Regex match that exclude certain pattern

Question

I want to split the string around for comma( , ) or & . This is simple but I want to stop the match for any content between brackets. For example if I run on

sleeping , waking(sit,stop)

there need to be only one split and two elements

thanks in advance

Answer 1

This is a perfect example for the (*SKIP)(*FAIL) mechanism PCRE (and thus PHP ) offers.
You could come up with the following code:

<?php
$string = 'sleeping , waking(sit,stop)';
$regex = '~\([^)]*\)(*SKIP)(*FAIL)|[,&]~';
# match anything between ( and ) and discard it afterwards
# instead match any of the characters found on the right in square brackets
$parts = preg_split($regex, $string);
print_r($parts);
/*
Array
(
    [0] => sleeping 
    [1] =>  waking(sit,stop)
)
*/

?>

This will split any , or & which is not in parentheses.