*196*

Ever needed a quick way to multiply two numbers on your Linux or Unix system? A shell script can be a handy tool for this task. In this post, we’ll create a shell script to Multiply Two Numbers

## Method 1: Using Arithmetic Expansion (Bash)

This method is the most concise and modern way to perform arithmetic operations within the shell script itself.

```
#!/bin/bash
# Prompt the user for two numbers
read -p "Enter the first number: " num1
read -p "Enter the second number: " num2
# Perform multiplication using arithmetic expansion
product=$((num1 * num2))
# Display the result
echo "The product of $num1 and $num2 is: $product"
```

**Explanation:**

`#!/bin/bash`

specifies the interpreter for the script (Bash in this case).`read`

commands prompt the user for input and store them in variables`num1`

and`num2`

.`(( ))`

performs arithmetic expansion. Here,`num1 * num2`

multiplies the two numbers and assigns the result to`product`

.`echo`

displays the final message with the calculated product.

**Method 2: Using **`expr`

command

`expr`

commandThis method utilizes the `expr`

command for performing calculations.

```
#!/bin/bash
# Prompt the user for two numbers
read -p "Enter the first number: " num1
read -p "Enter the second number: " num2
# Perform multiplication using expr
product=`expr $num1 \* $num2` # Escape the asterisk for multiplication
# Display the result
echo "The product of $num1 and $num2 is: $product"
```

**Explanation:**

- Similar to the first method for prompting for input.
`expr`

command is used for arithmetic operations. Here,`$num1 \* $num2`

performs the multiplication with escaping the asterisk (`*`

) to avoid conflicts with filename globbing.- The result is stored in the
`product`

variable using backticks. `echo`

displays the final message.

**Saving and Running the Script**

- Save the script as a file with a
`.sh`

extension (e.g.,`multiply.sh`

). - Make the script executable using
`chmod +x multiply.sh`

. - Run the script from your terminal:
`./multiply.sh`

.

These scripts provide a basic way to multiply two numbers using shell scripting. You can modify them further to accept arguments from the command line or perform more complex calculations.