User Interaction And Arithmetic Operations In Shell Script

What is User Interactions?

-> In the previous blog we have seen that if we have to print the name then we were setting it in the script only. For Example

#!/bin/bash
name="Bhaskar"
echo "Name is $name"

-> But if we want to take this value from the User then how to do that, we are going to see. It means that we are going to interact with the user-

#!/bin/bash

echo "Enter your name - "
read name # We have to use the read command to declare the variable

echo "Your name is $name "

Output -

-> When I run the Script then it will wait for me to enter the name as shown in below image -

-> When I enter the name, it will print the message

-> If can use this also

#!/bin/bash

read -p "Enter Your Name - " name

echo "Your name is $name "

Output -

Arithmetic Operations

-> Now we are going to perform some arithmetic operations using the shell script -

We can perform arithmetic operations using the following ways -

1. Using let Command

Example -

#!/bin/bash

a=10
b=5

let sum=$a+$b
echo "Sum is $sum"

let sub=$a-$b
echo "Sub is $sub"

let mul=$a*$b
echo "Mul is $mul"

let div=$a/$b
echo "Div is $div"

1. Using (( ))

Example

#!/bin/bash

a=10
b=5

echo "Addition is $(($a+$b))"
echo "Subtraction is $(($a-$b))"
echo "Multiplication is $(($a*$b))"
echo "Division is $(($a/$b))"

Output -