Some useful bash functions to be included (sourced) in your bash scripts

bash_functions.sh

# promptyn "{message}" {default_answer}
#   $1 "{message}"      like "Do you wish to procede? [Yn]"
#   $2 {default_answer} you can pass default value, just notify that in message above
# @return
#   0 for any of y, Y, yes, YAYA, yabbadabbadoo
#   1 for any of n, N, Nein, nikako, nonononoooo
promptyn() {
  while true; do
    read -p "$1 " yn
    CHOICE=${yn:0:1}
    case ${CHOICE:-$2} in
      [Yy]* ) return 0;;
      [Nn]* ) return 1;;
      * ) echo "Please answer yes or no.";;
    esac
  done
}

# CheckTask
#  $1 Message
#  $2 Variable name
CheckTask() {
  if [ "$BTN_AUTO" == "1"]; then
    eval ${2}=1
    return
  fi
  while true; do
    read -p "$1 " yn
    CHOICE=${yn:0:1}
    case ${CHOICE:-${!2}} in
      [Yy1]* ) eval ${2}=1 ; return ;;
      [Nn0]* ) eval ${2}=0 ; return ;;
      * ) echo "Please answer [ 1 y yes ] or [ 0 n no ] or [ENTER] to keep unchanged.";;
    esac
  done
}