[andrelaszlo]

A lot of the power of expect seems to come from the fact that it's (normally) configured/scripted in Tcl

https://linux.die.net/man/1/expect

I really like that it, like the article mentions, just looks like config for basic scripts but also scales to whatever you need it to do.

[pjmlp]

In our application server written in Tcl/C, the configuration files were a Tcl DSL, the server would search for specific extensions and source the files, done.

[AceJohnny2]

indeed, and other ports of Expect (Perl Pexpect, Python PyExpect) feel awkward as the constructs don't map quite as well to those languages.