title: Difference between interact, expect and exit in expect script
body: <p>I have a expect script as follow.</p>
  
  <pre><code>#!/usr/bin/expect
  
  set timeout 20
  
  spawn "some_script.sh"
  
  expect "Enter Auth Username:"
  send "username\n"
  
  expect "Enter Auth Password:"
  send "password\n"
  
  expect/interact/exit
  </code></pre>
  
  <p>I would like to know what is different between using expect/interact/exit.</p>
  
  <p>Thanks!</p>