The correct way to delete all files older than 2 days in PHP

Just curious

        $files = glob(cacheme_directory()."*");
        foreach($files as $file)
        {
            $filemtime=filemtime ($file);
            if (time()-$filemtime>= 172800)
            {
                unlink($file);
            }
        }

I just want to make sure if the code is correct or not. Thanks.

You should add an is_file() check, because PHP normally lists . and .., as well as sub-directories that could reside in the the directory you're checking.

Also, as this answer suggests, you should replace the pre-calculated seconds with a more expressive notation.

<?php
  $files = glob(cacheme_directory()."*");
  $now   = time();

  foreach ($files as $file) {
    if (is_file($file)) {
      if ($now - filemtime($file) >= 60 * 60 * 24 * 2) { // 2 days
        unlink($file);
      }
    }
  }
?>

Alternatively you could also use the DirectoryIterator, as shown in this answer. In this simple case it doesn't really offer any advantages, but it would be OOP way.

The easiest way is by using DirectoryIterator:

<?php
if (file_exists($folderName)) {
    foreach (new DirectoryIterator($folderName) as $fileInfo) {
        if ($fileInfo->isDot()) {
        continue;
        }
        if ($fileInfo->isFile() && time() - $fileInfo->getCTime() >= 2*24*60*60) {
            unlink($fileInfo->getRealPath());
        }
    }
}
?>