How to prompt for yes or no in bash?

Question

How do I ask a yes/no type question in Bash?

I ask the question... echo "Do you like pie?"

And receive the answer... read pie

How do I do something if the answer is yes, or starts with y (so yes and yeah, etc, will work too).

Answer 1

I like to use the following function:

function yes_or_no {
    while true; do
        read -p "$* [y/n]: " yn
        case $yn in
            [Yy]*) return 0  ;;  
            [Nn]*) echo "Aborted" ; return  1 ;;
        esac
    done
}

So in your script you can use like this:

yes_or_no "$message" && do_something

In case the user presses any key other than [yYnN] it will repeat the message.