# !/bin/bash

if [ "$1" = "-n" ] && [ "$2" != "" ] && [ "$3" = "" ]
then
res=`echo - $2 | bc`
echo "Result : $res"

elif [ "$1" = "-i" ] && [ "$2" = "" ] && [ "$3" = "" ]
then
echo "Enter Choice :"
echo "1. Addition (a+b)"
echo "2. Multiplication (a*b)"
echo "3. Subtraction (a-b)"
echo "4. Division (a/b)"
echo "5. Negation (-a)"
read ch

case $ch in
  1)echo "Enter Two numbers: "
        read a
        read b
        res=`echo $a + $b | bc`
  ;;
  2)echo "Enter Two numbers: "
        read a
        read b
        res=`echo $a \* $b | bc`
  ;;
  3)echo "Enter Two numbers: "
        read a
        read b
        res=`echo $a - $b | bc`
  ;;
  4)echo "Enter Two numbers: "
        read a
        read b
        res=`echo "scale=2; $a / $b" | bc`
  ;;
  5)echo "Enter One number: "
        read a
        res=`echo - $a | bc`
  ;;
esac
echo "Result : $res"

elif [ "$1" = "-a" ] && [ "$2" != "" ] && [ "$3" != "" ]
then
res=`echo $2 + $3 | bc`
echo "Result : $res"

elif [ "$1" = "-d" ] && [ "$2" != "" ] && [ "$3" != "" ]
then
res=`echo "scale=2; $2 / $3" | bc`
echo "Result : $res"

elif [ "$1" = "-s" ] && [ "$2" != "" ] && [ "$3" != "" ]
then
res=`echo $2 - $3 | bc`
echo "Result : $res"

elif [ "$1" = "-m" ] && [ "$2" != "" ] && [ "$3" != "" ]
then
res=`echo $2 \* $3 | bc`
echo "Result : $res"

fi