A simple PHP function to delete files older than a given age. **Updated to delete files in subdirectories.**

delete_older_than.php

<?php

/**
 * A simple function that uses mtime to delete files older than a given age (in seconds)
 * Very handy to rotate backup or log files, for example...
 * 
 * $dir String whhere the files are
 * $max_age Int in seconds
 * return String[] the list of deleted files
 */

function delete_older_than($dir, $max_age) {
    $list = array();
  
    $limit = time() - $max_age;
  
    $dir = realpath($dir);
    var_dump($dir);
    if (!is_dir($dir)) {
        return;
    }
  
    $dh = opendir($dir);
    if ($dh === false) {
        return;
    }
  
    while (($file = readdir($dh)) !== false) {

        if ($file != "." && $file != "..") {

            $file = $dir . '/' . $file;
            if (!is_file($file)) {
                if(count(glob("$file/*")) === 0)
                    rmdir($file);
                delete_older_than($file, $max_age);
            }
        
            if (filemtime($file) < $limit) {
                $list[] = $file;
                unlink($file);
            }
        }
    }
    closedir($dh);
    return $list;
}


// An example of how to use:
$dir = "/my/backups";
$to = "my@email.com";

// Delete backups older than 7 days
$deleted = delete_older_than($dir, 3600*24*7);

$txt = "Deleted " . count($deleted) . " old backup(s):\n" .
    implode("\n", $deleted);

mail($to, "Backups cleanup", $txt);