Q:

PHP Order Second Array ASC by Key

I have an array inside an array that has the filename, modification time and size, but I need to be able to order the array either ascending or descending by each one of these properties.
I have the following, which gets the information
//SCAN THE DIRECTORY
$directories = scandir($dir);
$directinfo = array();
foreach($directories as $directory){
    if ($directory === '.' or $directory === '..') continue;
    if(!stat($dir.'/'.$directory)){

    } else {
        $filestat = stat($dir.'/'.$directory);
        $directinfo[] = array(
            'name' => $directory,
            'modtime' => $filestat['mtime'],
            'size' => $filestat['size']
        );
    }
}

The array is structured as so:
Array ( 
    [0] => Array ( 
        [name] => 0 Organisation Details 
        [modtime] => 1398164749 
        [size] => 4096
    ) 
    [1] => Array ( 
        [name] => 1 Permission Form 
        [modtime] => 1398164749 
        [size] => 4096 
    ) 
    [2] => Array ( 
        [name] => 6 Invoices 
        [modtime] => 1400802471 
        [size] => 4096 
    ) 
)

and then use this to output:
foreach($directinfo as $dirInfo){
    foreach($dirInfo as $key=>$drInfo){
        echo "Output: ".$key."=>".$drInfo."<br />";
    }
}

But I need to arrange the array before this, and somehow make it so I don't need two arrays or I'm suspecting the ordered output wouldn't work.
I've looked at array_multisort but can't figure out how this would work in this instance.
Any help with this is really appreciated.

A:

Using example #3 on the array_multisort manual page:
$directories = array( 
array('name'=>'filec','modtime'=>'12303403434','size'=>'12401'),
array('name'=>'fileb','modtime'=>'12303403432','size'=>'12400'), 
array('name'=>'filez', 'modtime'=>'12304445405','size'=>'65200')
);

// Obtain a list of columns
$name = $modtime = $size = array();
foreach ($directories as $key => $row) {
    $name[$key]  = $row['name'];
    $modtime[$key] = $row['modtime'];
    $size[$key] = $row['size'];
}

// Sort the data with name ascending, modtime ascending, size ascending
array_multisort($name, SORT_ASC, $modtime, SORT_ASC, $size, SORT_ASC, $directories);

print_r($directories);

Online demo here

