#!/bin/bash

grep -F "pam_tid" /etc/pam.d/sudo >/dev/null
case $? in
  0)
    echo "TouchID unlock already in place"
    ;;

  1)
    sudo sed -i '' '1a\
auth       sufficient     pam_tid.so
    ' /etc/pam.d/sudo

    echo "TouchID unlock enabled"
    ;;

  *)
    echo "Error trying to read /etc/pam.d/sudo"
    ;;
esac