Convert a flat array of delimited values into a hierarchical array

Question

I am working with a permission system where I have to convert a single level array (separated by underscores) to a multidimentional array. Any help with a function that fix this?

Input array:

Array
(
    [0] => dashboard
    [1] => dashboard_read
    [2] => dashboard_update
    [3] => dashboard_create
    [4] => dashboard_delete
    [5] => dashboard_search
    [6] => timeplan_event_read
    [7] => timeplan_event_search
    [8] => timeplan_read
    [9] => timeplan_search
    [10] => webhotel
    [11] => webhotel_read
    [12] => webhotel_update
    [13] => webhotel_create
    [14] => webhotel_delete
    [15] => webhotel_search
)

Output array:

array(
    'dashboard' => array(
        'read',
        'update',
        'create',
        'delete',
        'search'
    ),
    'timeplan' =>array(
        'read',
        'search',
        'event' => array(
            'read',
            'search'
        )
    ),
    'webhotel' =>array(
        'read',
        'update',
        'create',
        'delete',
        'search'
    ),
)

Answer 1

[akshay@localhost tmp]$ cat test.php
 <?php

 $array = array("dashboard","dashboard_read","dashboard_update","dashboard_create","dashboard_delete","dashboard_search","timeplan_event_read","timeplan_event_search","timeplan_read","timeplan_search","webhotel","webhotel_read","webhotel_update","webhotel_create","webhotel_delete","webhotel_search");


 function build_arr($array, $delim='_') 
 { 
   $output = array();
   foreach($array as $key)
   {
    $main = explode($delim, $key);
    if (count($main) < 2)
        continue;

        $bottom = &$output;
        while(count($main) > 1) 
        {
                $sub = array_shift($main);
                if (!isset($bottom[$sub]))
                {
                    $bottom[$sub]  =  array();
                }
                    $bottom = &$bottom[$sub];
        }
                $bottom[] = $main[count($main)-1];
    }
    return $output;
 }

    // Input
    print_r( $array);

    // Output
    print_r( build_arr($array) );


 ?>

Output

 [akshay@localhost tmp]$ php test.php
 Array
 (
     [0] => dashboard
     [1] => dashboard_read
     [2] => dashboard_update
     [3] => dashboard_create
     [4] => dashboard_delete
     [5] => dashboard_search
     [6] => timeplan_event_read
     [7] => timeplan_event_search
     [8] => timeplan_read
     [9] => timeplan_search
     [10] => webhotel
     [11] => webhotel_read
     [12] => webhotel_update
     [13] => webhotel_create
     [14] => webhotel_delete
     [15] => webhotel_search
 )

 Array
 (
     [dashboard] => Array
         (
             [0] => read
             [1] => update
             [2] => create
             [3] => delete
             [4] => search
         )

     [timeplan] => Array
         (
             [event] => Array
                 (
                     [0] => read
                     [1] => search
                 )

             [0] => read
             [1] => search
         )

     [webhotel] => Array
         (
             [0] => read
             [1] => update
             [2] => create
             [3] => delete
             [4] => search
         )

 )