Drupal snippet - report missing files

drupal_missing_files.php

<?php

$purge = FALSE;

$result = db_query('SELECT fid, filename, filepath FROM {files}');
$i = 1;
$out = "MISSING FILES:\n";
while ($f = db_fetch_object($result)) {
  $dest = file_create_path($f->filepath);
  if (!file_exists($dest)) {
    $out .= $i++ . '. ' . $f->filepath;
    if ($purge) {
      if (db_query('DELETE FROM {files} WHERE fid=%d', $f->fid)) {
        $out .= ' (cleaned)';
      }
    }
    $out .= "\n";
  }
}
if ($i == 1) {
  $out .= "Congratulation, no file is missing!\n";
}
return $out;