function exceptionHandler ($e) {

     $fileHandle = fopen("error_log_file.log", "ab");

     fwrite($fileHandle,"Problem: " . $e->getMessage() .
      " in file " . $e->getFile() .
      ", on line " . $e->getLine() . "\n");
     fclose($fileHandle);
    }

    set_exception_handler('exceptionHandler');