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. This allows one to step through program
code in the debugger without messing up the terminal settings of the
program being debugged or having debugger output overwrite program output.
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
debuggeds IO to the slave (tty command of gdb). Thereafter, when running
the program under the debugger, its I/O will occur on the device on which
pty is running.
When you are finished using pty, you must manually kill it. When pty
starts it also prints out its pid.