SerialTerm is a very simple command line tool to output data received from a serial device. It's built in ruby, and the serialport gem does most of the heavy lifting.
I've only tested this with one device but it should work for anything that uses a serial output. If you find errors/exceptions feel free to report them or fix them and issue a pull request.
To install, just run:
$ gem install sterm
$ sterm DEVICE_PATH [-b BAUD_RATE -d DATA_BITS -s STOP_BITS -e LINE_ENDING]
Default baud rate is 115200
Default data bits is 8
Default stop bits is 1
LINE_ENDING is the hex value of the desired terminating string.
Default line ending is 0d0a (which is "\r\n" in hex).
Bug reports and pull requests are welcome on GitHub at https://github.com/guineec/serial-term.
This program is licensed under the GNU GPLv2.0 as required by the use of serialport.