statserial(1) on Linux
The text 66c5cde9c059, as Debian 3.0 (Woody), Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 1.3 (Bo), Debian 1.2 (Rex), Debian 1.1 (Buzz) shipped it.
display serial port modem status lines
Flags it lists
-
-d -
-n -
-x