Write a shell script to simulate a simple calculator program to perform addition substraction multiplication and division?

Answer 1

input="yes"

while [[ $input = "yes" ]]

do

echo "------------"

echo "Calculator"

echo "------------"

PS3="Press 1 for Addition, 2 for subtraction, 3 for multiplication and 4 for division: "

select math in Addition Subtraction Multiplication Division

do

case "$math" in

Addition)

echo "Enter first no:"

read num1

echo "Enter second no:"

read num2

result=<code>expr $num1 + $num2</code>

echo Answer: $result

break

;;

Subtraction)

echo "Enter first no:"

read num1

echo "Enter second no:"

read num2

result=<code>expr $num1 - $num2</code>

echo Answer: $result

break

;;

Multiplication)

echo "Enter first no:"

read num1

echo "Enter second no:"

read num2

result=<code>expr $num1 \* $num2</code>

echo Answer: $result

break

;;

Division)

echo "Enter first no:"

read num1

echo "Enter second no:"

read num2

result=$(expr "scale=2; $num1/$num2" | bc)

echo Answer = $result

break

;;

*)

echo Choose 1 to 4 only!!!!

break

;;

esac

done

echo "Do you want to calculate again(yes/no):"

read input

echo "Thank you for using this program"

done

Answer 2

1. Echo "Enter first number:"
2. Read n1
3. Echo "Enter Second number:"
4. Read n2
5. Echo "Enter operation to be carried out that is +, - , / or X"
6. Read opr
7. If [ opr=="+" ]
8. Then
9. echo $(( $a + $b ))
10. elif [ opr=="-"]
11. then
12. echo $(( $a - $b ))
13. elif [ opr=="/" ]
14. then
15. echo $(( $a / $b ))
16. elif [ opr=="X" ]
17. then
18. echo $(( $a * $b ))
19. fi