It was possible with the oldtelnet interface using something like
(echo admin ; echo help) | nc localhost 4212
That's now working with the lua one (but not the cleanest way).
(cherry picked from commit f5b8b43a9e210a70e016871db6bab36929d6b866)
Signed-off-by: Rémi Duraffort <ivoire@videolan.org>