[theamk]

Sure, but is it worth learning TCL for a few edge-cases? I like python, so I used "pexpect" in the past. I am sure other languages have such libraries too.

And if you are going for solid production, you probably want to re-implement "expect" anyway -- so all input is whitelisted and unexpected messages are flagged. You probably don't what to break your expensive 1990's industrial device because you were driving it with expect script, and it cheerfully ignored "WARNING RESERVE BATTERY DEAD, REPLACE BEFORE POWER OFF" messages.