if (file_exists($this->file) && is_readable($this->file) && is_writable($this->file)) {
   echo $this->file . "\n\n";
   $contents = file_get_contents($this->file);

   $foo = preg_replace($this->search, $this->replace, $contents);			

   file_put_contents($this->file, $contents);
			
   return true;

} else {
   ...
}