How to use expect with optional prompts?

Question

Let\'s say I am trying to write an expect script for a test.sh that has three prompts: prompt1, prompt2, prompt3.

My code is like this:

Answer 1

As long as you have a case that will be always be expected to hit and don't include an exp_continue in that case, you can can remove duplication and handle optional prompts easily:

expect "prompt1"
send "pass1"
expect { 
    "prompt2" { 
        send "pass2"
        exp_continue
    }
    "prompt3" {
        send "pass3"
    }
}

Answer 2

You can expect multiple things:

expect { 
    "prompt2" { 
        send "pass2"
        expect "prompt3"
        send "pass3"
    }
    "prompt3" {
        send "pass3"
    }
}