The venerable “expect”

About: Bruno Sutic, github.com/bruno-/
 Rails & Javascript developer
 Ideal Project Group, Chicago

What is expect? • a classic Unix tool • enables automating *everything* in the terminal • written in 1990, Tcl

Can’t script everything • ssh password entry? • sudo password entry? • doing multiple ssh “hops”, usually password protected
 (enterprises, telecoms) • interactive command line applications (tmux) • (short demo)

Expect is… • surprisingly easy to learn • powerful • easily available (installed by default on OS X) • does not replace scripting, use it for small % of tasks

Demo
 automating ssh tasks

Commands summary • spawn - starts a program • expect - “listens” for output • send - “types” program input • interact - gives control to the user

Commands summary • log_user 0 - make the script quiet • puts - print to the screen • set timeout 10
 …
 timeout { exit 1 }

My real-world usage examples • Ericsson NT - automating SSH connections (3-4 hops) • Automated testing for tmux plugins • tmux plugin manager • tmux copycat

Questions?