interceptty is designed to sit between a serial port (or other terminal device,
or program, or socket, or something connected to a file descriptor) and a
program which is communicating with that device, recording everything that goes
back and forth between the two. It does this by opening the real device,
creating a pseudo-tty, then forwarding everything between the two, recording
whatever it sees. It has a number of options that let you fine-tune the devices
it uses and the terminal options for the real device.

With the support for various backend types, interceptty is also useful to
create a fake serial port that will talk to the network or to a program you've
written.

The output of interceptty is a somewhat ugly, rudimentary format. It can be
postprocess through interceptty-nicedump, an included Perl script.

Homepage:
http://www.suspectclass.com/sgifford/interceptty/
