php - regexp split string by commas and spaces, but ignore the inside quotes and parentheses

Question

I need split string by commas and spaces, but ignore the inside quotes, single quotes and parentheses

$str = "Questions, "Quote",'single quote','comma,inside' (inside parentheses) space #specialchar";

so that the resultant array will have

[0]Questions
[1]Quote
[2]single quote
[3]comma,inside
[4]inside parentheses
[5]space
[6]#specialchar

my atual regexp is

$tags = preg_split("/[,s]*[^ws]+[s]*/", $str,0,PREG_SPLIT_NO_EMPTY);

but this is ignoring special chars and stil split the commas inside quotes, the resultant array is :

[0]Questions
[1]Quote
[2]single quote
[3]comma
[4]inside
[5]inside parentheses
[6]space
[7]specialchar

ps: this is no csv

Many Thanks

Answer 1

This will work only for non-nested parentheses:

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

    $tags = preg_split($regex, $str, -1,
                         PREG_SPLIT_NO_EMPTY
                       | PREG_SPLIT_DELIM_CAPTURE);

The ++ and *+ will consume as much as they can and give nothing back for backtracking. This technique is described in perlre(1) as the most efficient way to do this kind of matching.