filecache.php

<?php
// https://evertpot.com/107/
// Our class
class FileCache {

  // This is the function you store information with
  function store($key,$data,$ttl) {

    // Opening the file
    $h = fopen($this->getFileName($key),'w');
    if (!$h) throw new Exception('Could not write to cache');
    // Serializing along with the TTL
    $data = serialize(array(time()+$ttl,$data));
    if (fwrite($h,$data)===false) {
      throw new Exception('Could not write to cache');
    }
    fclose($h);

  }

  // General function to find the filename for a certain key
  private function getFileName($key) {
      global $DBCONFIG;
      return '/tmp/s_cache-' . $DBCONFIG->name . "-" . md5($key);

  }

  // The function to fetch data returns false on failure
  function fetch($key) {

      $filename = $this->getFileName($key);
      if (!file_exists($filename) || !is_readable($filename)) return false;

      $data = file_get_contents($filename);

      $data = @unserialize($data);
      if (!$data) {

         // Unlinking the file when unserializing failed
         unlink($filename);
         return false;

      }

      // checking if the data was expired
      if (time() > $data[0]) {

         // Unlinking
         unlink($filename);
         return false;

      }
      return $data[1];
    }

}

?>