Bash script to prompt user to choose from list of options. (Bash makes everything so hard.)

options.sh

#!/usr/local/bin/bash

stty -echo
tput civis

function cleanup() {
  stty echo
  tput cnorm
}

function interrupt() {
  cleanup
  exit
}

trap interrupt INT

if [ "$#" -le "1" ]; then
  echo "Error: Not enough options"
  kill -INT $$ # To stop exiting when run as source script
fi

selected=0

function echo_menu() {
  # Echo the menu with the selected option highlighted
  count=0
  tput sgr0
  echo -n " " # Indent
  for opt in "$@"; do
      if [ "$count" -eq "$selected" ]; then
          tput rev
      else
          tput sgr0
      fi
      echo -n "$opt"
      count=$(($count + 1))
      tput sgr0
      echo -n " " # Padding
  done
  echo
}

echo_menu "$@"

while read -rsn1 key; do
  case "$key" in
  $'\x1b')
      read -rsn1 -t 0.1 key
      if [ "$key" == "[" ]; then
          read -rsn1 -t 0.1 key
          case "$key" in
	  "A" | "D")
	      if [ "$selected" -gt "0" ]; then
	          selected=$(($selected - 1))
	      fi
	      tput cuu1
	      echo_menu "$@"
	      ;;
          "B" | "C")
	      if [ "$selected" -lt "$(($# - 1))" ]; then
		  selected=$(($selected + 1))
	      fi
	      tput cuu1
	      echo_menu "$@"
	      ;;
          esac
      fi
      ;;
  "" | "\n")
      selected_adjust=$(($selected + 1))
      export answer=${!selected_adjust} # Return value from function (only works when script is sourced)
      break
      ;;
  esac
done

cleanup

# +------------------------------------+
# | Example usage (in another script): |
# +------------------------------------+
#
# #!/bin/bash
# echo 'exit?'
# . ./options.sh Yes No # NOTE: the preceding dot is necessary to make the answer accessible
# if [ "$answer" == "Yes" ]; then
#   exit
# fi