The function get-serial-port-state queries various aspects of the state of the serial port associated with serial-port .
The argument
keys
should be a list of one or more of the keywords
:dsr
and
:cts
. These cause get-serial-port-state to check the DSR and CTS lines respectively.
The result state is a list giving the state of each line in the same order as they appear in the argument keys .