PHP list & serve gzipped files from dir

serve_gz_files.php

<?php
/**
 * Given a directory full of gzipped AVI files,
 * outpu a JSON array with the list of zipped video files in the dir.
 *
 * If a GET query param is provided for `file` then that specific
 * file is returned, uncompressed, with the .gz extension removed
 */

if (isset($_GET['file'])) {

  if (!file_exists($_GET['file'])) {
    http_response_code(404);
    exit;
  }

  header('Content-Type: video/x-msvideo');
  header('Content-Disposition: attachment; filename=' . substr($_GET['file'], 0, -3));
  echo file_get_contents("compress.zlib://" . $_GET['file']);
  exit;
}


$zipped_videos = glob('*.avi.gz');
echo json_encode($zipped_videos);