#!/bin/bash
#Lab 10
#Anh-Quan Dang
#040-793-157
#Section 323
#myCalc.sh

function add(){
     echo "add"
     ((total = $1 + $2))
     echo "$1 + $2 = (($total))"
}

function sub(){
     echo "sub"
     ((total = $1 - $2))
     echo "$1 - $2 = (($total))"
}
echo "Please enter C) Calculation or X for exit "
read choice
#first case
case $choice in
	c|C)
	   echo "Please enter an integer or X to exit"
	   read ans
	   #second case
   	   case $ans in
	       	  x|X)
             		   $exit
          	  ;;
		  *)
                         echo "+ for adding"
	                 echo "- for subtracting"
                    	 echo "X for exit"
          	         read choices
          			 #third case
				 case $choices in
        	        		 +)
                        		 clear
                       			 echo "works on +"
                         		 echo "Please enter an integer or X to exit"
                        		 read an
                         		 case $an in
                          		    x|X)
                                                 $exit
                                             ;;

					       *)
						add $ans $an
					     ;;
                          		 esac

                		 ;;

				-)
  		                      clear
        		                echo "Please enter an integer or X to exit"
               			         read an
                       			 echo "works on -"
                       			 case $an in
                       			 x|X)
						$exit
			       		;;
					 *)
                           		 sub $ans $an
                       			 ;;

                       			 esac

                			 ;;

             			  x|X)
                                         $exit
                                 ;;

			esac #end of third case

			;;
       	   x|X)
		$exit
  	   ;;
	   esac #end of second case
esac #end of first case