Empty - an expectlike tool to run command-line interactive programs in
UNIX shell-scripts

empty is an utility that provides an interface to execute and/or interact
with processes under pseudo-terminal sessions (PTYs). It can be used to
automate otherwise interactive programs like telnet, ssh, and ftp. In
some cases empty can be the simplest replacement for TCL/expect or other
(similar) programming tools.

Somewhat similar in functionality also to POTS modem chat(8) or the
scripting capabilities of minicom(1) however its small and general
purpose.