Exploring Expect: A Tcl-based Toolkit for Automating Interactive Programs

Expect is quickly becoming a part of every UNIX users toolbox. It allows you to automate Telnet, FTP, passwd, rlogin, and hundreds of other applications that normally require human interaction. Using Expect to automate these applications will allow you to speed up tasks and, in many cases, solve new problems that you never would have even considered before.
For example, you can use Expect to test interactive programs with no changes to their interfaces. Or wrap interactive programs with Motif-like front-ends to control applications by buttons, scrollbars, and other graphic elements with no recompilation of the original programs. You dont even need the source code! Expect works with remote applications, too. Use it to tie together Internet applications including Telnet, Archie, FTP, Gopher, and Mosaic.