public function cmdDeleteCurrency()
    {
        $id = $this->getParam(0);
        $all = $this->getParam('all');

        if (empty($id) && empty($all)) {
            $this->errorAndExit($this->text('Invalid command'));
        }

        $result = false;

        if (!empty($id)) {
            $result = $this->currency->delete($id);
        } else if (!empty($all)) {
            $deleted = $count = 0;
            foreach ($this->currency->getList(array('in_database' => true)) as $currency) {
                $count++;
                $deleted += (int) $this->currency->delete($currency['code']);
            }
            $result = ($count == $deleted);
        }

        if (empty($result)) {
            $this->errorAndExit($this->text('Unexpected result'));
        }

        $this->output();
    }