Split string by spaces exception on spaces in braces and quotes

split_string.php

$str = '3021e69d9d2569db27ce7b74ccaa98496007de09a1f4b94e45f48203d8727ac6 test.com [05/Jul/2011:07:28:57 +0000] 126.97.98.19 3021e69d9d2569db27ce7b74ccaa98496007de09a1f4b94e45f48203d8727ac6 70706DF22A809F33 REST.GET.OBJECT 1as21/foldera/file.png "GET //folder/test.php?AWSAccessKeyId=45dsgrg$5f&Expires=1310388787&Signature=Yehn847BhdsaiuernYmjne= HTTP/1.1" 206 - 47972352 209316737 54194091 7 "http://test.info/?url=http://ns.in/54325" "Mozilla/5.0 (Windows NT 6.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1" -';

$regex = <<<REGEX
       /"((?:[^"]*|)++)\"
      |\[((?:[^\]]*|)++)\]
      |[\s]
    /x
REGEX;

$out = preg_split($regex,$str, 0, PREG_SPLIT_DELIM_CAPTURE );

var_dump($out);

/**

array(27) {
  [0]=>
  string(64) "3021e69d9d2569db27ce7b74ccaa98496007de09a1f4b94e45f48203d8727ac6"
  [1]=>
  string(8) "test.com"
  [2]=>
  string(0) ""
  [3]=>
  string(0) ""
  [4]=>
  string(26) "05/Jul/2011:07:28:57 +0000"
  [5]=>
  string(0) ""
  [6]=>
  string(12) "126.97.98.19"
  [7]=>
  string(64) "3021e69d9d2569db27ce7b74ccaa98496007de09a1f4b94e45f48203d8727ac6"
  [8]=>
  string(16) "70706DF22A809F33"
  [9]=>
  string(15) "REST.GET.OBJECT"
  [10]=>
  string(22) "1as21/foldera/file.png"
  [11]=>
  string(0) ""
  [12]=>
  string(109) "GET //folder/test.php?AWSAccessKeyId=45dsgrg$5f&Expires=1310388787&Signature=Yehn847BhdsaiuernYmjne= HTTP/1.1"
  [13]=>
  string(0) ""
  [14]=>
  string(3) "206"
  [15]=>
  string(1) "-"
  [16]=>
  string(8) "47972352"
  [17]=>
  string(9) "209316737"
  [18]=>
  string(8) "54194091"
  [19]=>
  string(1) "7"
  [20]=>
  string(0) ""
  [21]=>
  string(40) "http://test.info/?url=http://ns.in/54325"
  [22]=>
  string(0) ""
  [23]=>
  string(0) ""
  [24]=>
  string(67) "Mozilla/5.0 (Windows NT 6.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1"
  [25]=>
  string(0) ""
  [26]=>
  string(1) "-"
}

*/