how to control the printer port for the use of resetting modems and other devices
and the reading the port for feedback
If you are looking for a CLI tool, I usually use minicom for RS-232 communication on Linux - It is available for FreeBSD too:
https://www.freebsd.org/cgi/man.cgi?minicom
It might work with a parallel port too.
looked around for minicom parallel port looks like mostly RS232
i found this
https://numato.com/product/8-channel-usb-gpio-module-with-analog-inputs
they also have eg code
maybe can adopt it
https://numato.com/product/8-channel-usb-gpio-module-with-analog-inputs
using Python