cu(1) on Linux
The text 3abd9b4d6cd9, as Debian 9 (Stretch) shipped it.
Call up another system
Flags it lists
-
-# -
--config -
--debug -
--escape -
--halfduplex -
--help -
--line -
--nostop -
--parity -
--phone -
--port -
--prompt -
--speed -
--system -
--version -
-E -
-I -
-a -
-c -
-d -
-e -
-h -
-l -
-n -
-o -
-p -
-s -
-v -
-x -
-z