week6.5

5. Write a shell program to simulate a simple calculator.

#!/bin/bash

# function to add two numbers
addition() {
  echo "$1 + $2 = $(($1 + $2))"
}

# function to subtract two numbers
subtraction() {
  echo "$1 - $2 = $(($1 - $2))"
}

# function to multiply two numbers
multiplication() {
  echo "$1 * $2 = $(($1 * $2))"
}

# function to divide two numbers
division() {
  if [ $2 -eq 0 ]; then
    echo "Error: division by zero"
  else
    echo "$1 / $2 = $(($1 / $2))"
  fi
}

# read the operator and two numbers from user input
echo "Enter operator (+, -, *, /):"
read operator
echo "Enter first number:"
read num1
echo "Enter second number:"
read num2

# call the appropriate function based on the operator
case $operator in
  +)
    addition $num1 $num2
    ;;
  -)
    subtraction $num1 $num2
    ;;
  \*)
    multiplication $num1 $num2
    ;;
  /)
    division $num1 $num2
    ;;
  *)
    echo "Error: invalid operator"
    ;;
esac