framework/console/controllers/HelpController.php
public function actionListActionOptions($action)
    {
        $result = Yii::$app->createController($action);

        if ($result === false || !($result[0] instanceof Controller)) {
            return;
        }

        /** @var Controller $controller */
        list($controller, $actionID) = $result;
        $action = $controller->createAction($actionID);
        if ($action === null) {
            return;
        }

        foreach ($controller->getActionArgsHelp($action) as $argument => $help) {
            $description = preg_replace("~\R~", '', addcslashes($help['comment'], ':')) ?: $argument;
            $this->stdout($argument . ':' . $description . "\n");
        }

        $this->stdout("\n");
        foreach ($controller->getActionOptionsHelp($action) as $argument => $help) {
            $description = preg_replace("~\R~", '', addcslashes($help['comment'], ':'));
            $this->stdout('--' . $argument . ($description ? ':' . $description : '') . "\n");
        }
    }
public function actionListActionOptions($action)
    {
        $result = Yii::$app->createController($action);

        if ($result === false || !($result[0] instanceof Controller)) {
            return;
        }

        /** @var Controller $controller */
        list($controller, $actionID) = $result;
        $action = $controller->createAction($actionID);
        if ($action === null) {
            return;
        }

        foreach ($controller->getActionArgsHelp($action) as $argument => $help) {
            $description = preg_replace("~\R~", '', addcslashes($help['comment'], ':')) ?: $argument;
            $this->stdout($argument . ':' . $description . "\n");
        }

        $this->stdout("\n");
        foreach ($controller->getActionOptionsHelp($action) as $argument => $help) {
            $description = preg_replace("~\R~", '', addcslashes($help['comment'], ':'));
            $this->stdout('--' . $argument . ($description ? ':' . $description : '') . "\n");
        }
    }
List all available options for the $action in machine readable format.
This is used for shell completion.

@param string $action route to action
@since 2.0.11