Bash Functions: Exercises, Solutions & Explanations

Last update on April 27 2024 13:15:28 (UTC/GMT +8 hours)

Greeting Function:

Write a Bash script that defines a function called greet that takes a name as an argument and prints a greeting message using that name.

Code:

# D#!/bin/bash

efine the greet function
greet() {
    local name="$1"  # Get the name from the first argument
    echo "Hello, $name! Welcome!"
}

# Call the greet function
greet "Maria"

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
Hello, Maria! Welcome!

Explanation:

In the exercise above,

Define a function called "greet()" using the greet() { ... } syntax.
Inside the function:

Use 'local' to declare a local variable 'name' to store the argument passed to the function.
Next use "echo" to print a greeting message containing the provided name.

Outside the function, we call "greet()" with the argument "Alice". You can replace "Alice" with any name you want to greet.

Addition Function:

Write a Bash script that defines a function called add that takes two numbers as arguments and prints their sum.

Code:

#!/bin/bash

# Define the add function
add() {
    local num1=$1
    local num2=$2
    local sum=$((num1 + num2))
    echo "The sum of $num1 and $num2 is: $sum"
}

# Call the add function with two numbers
add 10 20
add 100 200

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The sum of 10 and 20 is: 30
The sum of 100 and 200 is: 300

Explanation:

In the exercise above,

Define a function called "add()" using the add() { ... } syntax.
Inside the function:

We declare two local variables 'num1' and 'num2' to store the arguments passed to the function.
We calculate the sum of 'num1' and 'num2' and store it in the 'sum' variable.
Finally, we use "echo" to print a message showing the sum.

Subtraction Function:

Write a Bash script that defines a function called subtract that takes two numbers as arguments and prints their difference.

Code:

#!/bin/bash

# Define the subtract function
subtract() {
    local num1=$1
    local num2=$2
    local difference=$((num1 - num2))
    echo "The difference between $num1 and $num2 is: $difference"
}

# Call the subtract function with two numbers
subtract 35 12
subtract 40 60

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The difference between 35 and 12 is: 23
The difference between 40 and 60 is: -20

Explanation:

In the exercise above,

Define a function called "subtract()" using the subtract() { ... } syntax.
Inside the function:

Declare two local variables 'num1' and 'num2' to store the arguments passed to the function.
Calculate the difference between 'num1' and 'num2' and store it in the 'difference' variable.
Finally, use "echo" to print a message showing the difference.

Multiplication Function:

Write a Bash script that defines a function named multiply that takes two numbers as arguments and prints their product.

Code:

#!/bin/bash

# Define the multiply function
multiply() {
    local num1=$1
    local num2=$2
    local product=$((num1 * num2))
    echo "The product of $num1 and $num2 is: $product"
}

# Call the multiply function with two numbers
multiply 12 6
multiply 100 -20

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The product of 12 and 6 is: 72
The product of 100 and -20 is: -2000

Explanation:

In the exercise above,

Define a function called "multiply()" using the multiply() { ... } syntax.
Inside the function:

Declare two local variables 'num1' and 'num2' to store the arguments passed to the function.
Calculate the product of 'num1' and 'num2' and store it in the 'product' variable.
Finally, use "echo" to print a message showing the product

Division Function:

Write a Bash script that defines a function called divide that takes two numbers as arguments and prints their division.

Code:

#!/bin/bash

# Define the divide function
divide() {
    local num1=$1
    local num2=$2

    # Check if num2 is zero to avoid division by zero error
    if [ $num2 -eq 0 ]; then
        echo "Error: Division by zero"
        exit 1
    fi

    local result=$(bc <<< "scale=2; $num1 / $num2")
    echo "The division of $num1 by $num2 is: $result"
}

# Call the divide function with two numbers
divide 24 5
divide 13 330

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The division of 24 by 5 is: 4.80
The division of 13 by 330 is: .03

Explanation:

In the exercise above,

Define a function called "divide()" using the divide() { ... } syntax.
Inside the function:

Declare two local variables 'num1' and 'num2' to store the arguments passed to the function.
Check if 'num2' is zero to avoid the division by zero error. If it is, we print an error message and exit the script.
Use "bc" command-line calculator to perform floating-point division with two decimal places (scale=2).
Finally print a message showing the result of the division.

Factorial Function:

Write a Bash script that implements a function called factorial that calculates and prints the factorial of a given number.

Code:

#!/bin/bash

# Define the factorial function
factorial() {
    local num=$1
    local result=1

    # Check if num is negative
    if [ $num -lt 0 ]; then
        echo "Error: Factorial is not defined for negative numbers"
        exit 1
    fi

    # Calculate factorial
    for ((i = 1; i <= num; i++)); do
        result=$((result * i))
    done

    echo "The factorial of $num is: $result"
}

# Call the factorial function with a number
factorial 5
factorial 10

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The factorial of 5 is: 120
The factorial of 10 is: 3628800

Explanation:

In the exercise above,

Define a function called "factorial()" using the factorial() { ... } syntax.
Inside the function:

Declare a local variable 'num' to store the argument passed to the function.
Declare another local variable 'result' and initialize it to 1.
Check if 'num' is negative. If it is, we print an error message and exit the script.
Finally calculate the factorial of 'num' using a loop and store the result in the 'result' variable.

Maximum Function:

Write a Bash script that defines a function named maximum that takes two numbers as arguments and prints the maximum of the two.

Code:

#!/bin/bash

# Define the maximum function
maximum() {
    local num1=$1
    local num2=$2

    if [ $num1 -gt $num2 ]; then
        echo "The maximum of $num1 and $num2 is: $num1"
    else
        echo "The maximum of $num1 and $num2 is: $num2"
    fi
}

# Call the maximum function with two numbers
maximum 100 115
maximum -5 -9

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The maximum of 100 and 115 is: 115
The maximum of -5 and -9 is: -5

Explanation:

In the exercise above,

Define a function called "maximum()" using the maximum() { ... } syntax.
Inside the function:

Declare two local variables 'num1' and 'num2' to store the arguments passed to the function.
Use an if-else statement to compare 'num1' and 'num2'.
If 'num1' is greater than 'num2', we print a message showing 'num1' as the maximum.
Otherwise, print a message showing 'num2' as the maximum.

Minimum Function:

Write a Bash script that defines a function called minimum that takes two numbers as arguments and prints the minimum of the two.

Code:

#!/bin/bash

# Define the minimum function
minimum() {
    local num1=$1
    local num2=$2

    if [ $num1 -lt $num2 ]; then
        echo "The minimum of $num1 and $num2 is: $num1"
    else
        echo "The minimum of $num1 and $num2 is: $num2"
    fi
}

# Call the minimum function with two numbers
minimum 100 115
minimum -12 -15

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The minimum of 100 and 115 is: 100
The minimum of -12 and -15 is: -15

Explanation:

In the exercise above,

Define a function called "minimum()" using the minimum() { ... } syntax.
Inside the function:

Declare two local variables 'num1' and 'num2' to store the arguments passed to the function.
Use an if-else statement to compare 'num1' and 'num2'.
If 'num1' is less than 'num2', we print a message showing 'num1' as the minimum.
Otherwise, print a message showing 'num2' as the minimum.

Square Function:

Write a Bash script that defines a function named square that takes a number as an argument and prints its square.

Code:

#!/bin/bash

# Define the square function
square() {
    local num=$1
    local square=$((num * num))
    echo "The square of $num is: $square"
}

# Call the square function with a number
square 12
square 34

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The square of 12 is: 144
The square of 34 is: 1156

Explanation:

In the exercise above,

Define a function called "square()" using the square() { ... } syntax.
Inside the function:

Declare a local variable 'num' to store the argument passed to the function.
Calculate the square of 'num' and store it in the 'square' variable.
Finally, use "echo" to print a message showing the square.

10.

Power Function:

Write a Bash script that implements a function called power that takes two numbers as arguments and prints the result of raising the first number to the power of the second number.

Code:

#!/bin/bash

# Define the power function
power() {
    local base=$1
    local exponent=$2
    local result=$((base ** exponent))
    echo "The result of $base raised to the power of $exponent is: $result"
}

# Call the power function with two numbers
power 2 5
power 100 2

Output:

ad@DESKTOP-3KE0KU4:~$ ./test1.sh
The result of 2 raised to the power of 5 is: 32
The result of 100 raised to the power of 2 is: 10000

Explanation:

In the exercise above,

Define a function called "power()" using the power() { ... } syntax.
Inside the function:

Declare local variables 'base' and 'exponent' to store the arguments passed to the function.
Calculate the result of raising 'base' to the power of 'exponent' using the ** operator.
Finally, use "echo" to print a message showing the result.

Bash Editor:

More to Come !

Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.