dump conf from running nginx process

Is it possible to get which conf the nginx is using only from a running nginx process? To get the conf file path. sometimes `ps aux` reveal it, sometimes it doesn't. It might be just something like `nginx: master process /usr/sbin/nginx` (same as `/proc/PID/cmdline`) 1. So is `nginx -V` the only solution? 2. From [this question](https://serverfault.com/a/436239/59379), is it possible to dump conf data structure from nginx process directly? Or at least dump the conf file path?