pty is a tool to help debug console programs which take the terminal out of
canonical mode, by allowing the program being debugged and the debugger to run
on separate terminal devices.

To use pty, the programmer changes to the terminal device where he or she
wishes to interact with the program to be debugged, and at the shell
prompt, runs pty with no arguments.  Pty will print out the filename of the
slave side of the pseudo-terminal it has opened.  Inside the debugger,
running in another terminal device, one then redirects the program to be
debugged's IO to the slave (tty command of gdb).  When you are finished
using pty, you must manually kill it.  When pty starts it prints out its
pid.

WWW: http://www.mammothcheese.ca/munger.html