Serial Line Sniffer is a serial port logging utility. It listens to the specified serial port and logs all data going through this port in both directions.
Changes: A real serial port can now be used (instead of a pty), device(s) can now optionally be locked, port parameters are now automatically synchronized between the ports, the timestamping code now gives more precise output, options can now be read from rc files, and some minor bugs were fixed.