#!/bin/sh

# Define ask_yn, which asks a yes or no question and defaults to the specified choice.
# Outputs 1 for yes and 0 for no

ask_yn() {
    default=${2:-"y"}
    default=$(printf "%s" "$default" | tr '[:upper:]' '[:lower:]')
    
    # Set prompt string
    case "$default" in
        y)  prompt="Y/n" ;;
        n)  prompt="y/N" ;;
        *)  printf "Invalid default answer\n"; exit 1 ;;
    esac
    
    while true; do
        trap 'stty sane; exit' INT
        printf "%s (%s): " "$1" "$prompt"
        stty raw -echo
        answer=$(head -c 1) || exit
        stty -echo
        printf "\n"
        case "$answer" in
            "" ) answer="$default"; break;;
            y|Y) answer="y"; break;;
            n|N) answer="n"; break;;
        esac
    done
    
    case "$answer" in
        y|Y) printf "1";;
        n|N) printf "0";;
    esac
}