Finding latest file's name and modification time in PHP - php

Question

I search a director with glob function and get the matched files' list. Then by checking filemtime of the files I create a map. Then sort the map with respect to file dates. At last I get latest file's name and modification time. My code is like this. It works well for small directories, but it's slow for big directories. I wonder whether is there a faster/clever way?
$fileList = array();
// $id = is the argument of this function
$files = glob('myfolder'.DS.'someone'.$id.'*.txt');
if (empty($files)) {
return 0;
}
foreach ($files as $file) {
$fileList[filemtime($file)] = $file;
}
if (sizeof($files) > 1) {
ksort($fileList);
}
$latestFilename = end($fileList);
$fileLastModifDate = filemtime( $latestFilename );

Answer 1

i suspect that your "mapping" is actually creating a hash table, and then the sort is not efficiant as one might expect, i would try this: (this is the basic, u can fancy it up)
class file_data
{
public $time; // or whatever u use
public $file;
}
$arr =new array ();
foreach ($files as $file) {
$new_file = new file_data ();
$file_data->time = filetime($file);
$file_data->file = $file;
array_push ($arr,$file_data);
}
function file_object_compare ($a,$b)
{
if ($a->time > $b->time) return -1;
// etc... i.e 0 eual 1 otherwise
}
//and then u sort
usort ($arr,"file_object_compare");
// or
// and this is probably better, if u only need this paricular sorting
function file_object_compare ($a,$b)
{
if (filetime($a)> filetime($b)) return -1;
// etc... i.e 0 eual 1 otherwise
}
usort ($files,"file_object_compare");