Expect is a tool for automating interactive applications
such as telnet, ftp, passwd, fsck, rlogin, tip, etc. Expect
really makes this stuff trivial. Expect is also useful for
testing these same applications. And by adding Tk, you can
also wrap interactive applications in X11 GUIs.
Expect can make easy all sorts of tasks that are prohibitively
difficult with anything else. You will find that Expect is an
absolutely invaluable tool - using it, you will be able to
automate tasks that you've never even thought of before - and
you'll be able to do this automation quickly and easily.