How to save call_user_func_array() function output

i am trying to make a static site generator which works with a great routing class.

if (php_sapi_name() === "cli") {
    foreach ($router->get() as $route) {
        $out = ob_get_contents();
        call_user_func_array($route['function'], array());
        ob_end_clean();
        file_put_contents("./temp/" . $route['expression'] . ".html", $out);
    }
}

So i am trying this I can see the compiled html code through terminal but file is empty. How can I save output of call_user_func_array() function?

Answer

See this example:

if (php_sapi_name() === "cli") {
    // Start output buffering here
    ob_start();
    foreach ($router->get() as $route) {
        call_user_func_array($route['function'], array());
        // get output of `$route['function']` to $out variable
        $out = ob_get_contents();
        // clean buffer
        ob_clean();

        file_put_contents("./temp/" . $route['expression'] . ".html", $out);
    }
    // stop output buffering
    ob_end_clean();
}