We just merged #18432 which adds a new feature to the curl API: notifications. This is not visible in the curl command line, only for applications using libcurl. What are curl notifications? The application can register a callback function and data that is invoked when “things happened” during multi handle processing. It’s a feature of curl’s multi handle and you use it like this: struct priv { /* ... */ }; static void ntfy_cb(CURLM *multi, unsigned int notification, CURL *easy, void ...
