The venerable "expect"

Transcript

1. The venerable “expect”

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

   Group, Chicago

3. What is expect? • a classic Unix tool • enables

   automating *everything* in the terminal • written in 1990, Tcl

4. 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)

5. 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

6. Demo
 automating ssh tasks

7. Commands summary • spawn - starts a program • expect

   - “listens” for output • send - “types” program input • interact - gives control to the user

8. Commands summary • log_user 0 - make the script quiet

   • puts - print to the screen • set timeout 10
 …
 timeout { exit 1 }

9. My real-world usage examples • Ericsson NT - automating SSH

   connections (3-4 hops) • Automated testing for tmux plugins • tmux plugin manager • tmux copycat

10. Questions?