How to find all substrings of a string in PHP

Question

I need to convert strings of the form

\"a b c\"

into arrays of the form

Array
(
    [0] => a
    [1] => a b
    [2] =         


        

Answer 1

And this question will not be complete without the recursive answer:

function get_substrings($str){
    $len = strlen($str);
    $ans = array();
    $rest = array();
    for ($i = 1; $i <= $len; $i++) {                 
        $ans[] = substr($str, 0, $i);        
    }
    if($str){
        $rest = get_substrings(substr($str, 1));
    }
    return array_merge($ans, $rest);
}

$subs = get_substrings("abc");
print_r($subs);