转换数组的结构

I have the following array:

Array ( 
   [0] => Information.pdf
   [1] => Presentation.pdf
   [2] => Brochure.pdf
) 

I want to convert it into a nested array in the following format using PHP to make it compatible with the CakePHP 2.1.1 email class:

Array (  
   [Information.pdf] => Array ( 
        [file] => /files/Information.pdf 
        [mimetype] => application/pdf  
   ) 
   [Presentation.pdf] => Array ( 
        [file] => /files/Presentation.pdf 
        [mimetype] => application/pdf  
   ) 
   [Brochure.pdf] => Array ( 
        [file] => /files/Brochure.pdf 
        [mimetype] => application/pdf  
   ) 
)

Any ideas on how to do this? The "mimetype" can be hardcoded.

$nested = array();
foreach($flat as $filename) {
    $nested[$filename] = array(
        'file' => '/files/'.$filename,
        'mimetype' => 'application/pdf'
    );
};

For mimetype guessing, the fileinfo extension would be a good choice.

$newArr = array();
foreach($arr as $val) {
    $newArr[$val] = array(
        "file"      =>  "/files/".$val,
        "mimetype"  =>  "application/pdf"
    );
}

Use a foreach to iterate through the array items and use mime_content_type() to get the mimetype.

$temp = array(); //A temporary array to store new array
foreach($array as $filename) { //Supposing $array is your original array
    $file = '/files/'.$filename;
    $temp[$filename] = array(
        'file' => $file,
        'mimetype' => mime_content_type($file)
    );
};

<?php
$arr = array('Information.pdf','Presentation.pdf','Brochure.pdf'); //current array
$new_arr = array();
foreach($arr as $key=>$value){
    $val = explode(".",$value);
    $new_arr[$value]=array('file'=>"/files/".$value,'mimetype'=>"application/".$value[1]);
}
?>