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[email protected] · Mon Nov 27 2023

With relevant PHP code discuss the steps required to upload an image to a web server. short easy answer

Sure, here are the basic steps required to upload an image to a web server using PHP:

Create an HTML form with enctype="multipart/form-data" for uploading the image.
Use PHP to handle the form submission and move the uploaded file to a specified directory on the server.

Here's an example of the PHP code:

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $targetDir = "uploads/"; // Specify the directory where the file will be stored
    $targetFile = $targetDir . basename($_FILES["fileToUpload"]["name"]);
    $uploadOk = 1;
    
    // Check if image file is an actual image or fake image
    $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]);
    if($check !== false) {
        move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $targetFile);
        echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";
    } else {
        echo "File is not an image.";
    }
}
?>

<!DOCTYPE html>
<html>
<body>

<form action="<?php echo $_SERVER['PHP_SELF'];?>" method="post" enctype="multipart/form-data">
    Select image to upload:
    <input type="file" name="fileToUpload" id="fileToUpload">
    <input type="submit" value="Upload Image" name="submit">
</form>

</body>
</html>

Replace "uploads/" with the actual directory where you want to store the uploaded images.

Remember to ensure proper file permissions on the server for the upload directory, for security reasons.

Create a web application to register employee details viz. employee number, name, department, basic salary and store the information in a database. Provide functionalities to (i) calculate the gross salary (basic + HRA=15% of basic + Other Allowance=10% of basic) to complete the details of an employee and (ii) accept department name and display the employee details department wise

To create a web application to register employee details and perform the specified functionalities, you can use HTML for the front-end forms and PHP for the backend processing. Additionally, you'll need a database to store and retrieve the employee details. Here's a simplified example using PHP and MySQL:

Create a Database: Create a MySQL database named "employees" with a table named "employee_details" containing columns for employee number, name, department, basic salary, and other calculated fields like HRA and Other Allowance.
Create the HTML Form for Employee Registration: You can create an HTML form to accept employee details and submit the data to the PHP script for processing.
PHP Script for Storing Employee Details: Create a PHP script to handle the form submission and store the employee details in the database.
PHP Functions for Calculating Gross Salary: Write PHP functions to calculate the gross salary based on the basic salary, HRA (15% of basic), and Other Allowance (10% of basic).
PHP Script for Displaying Employee Details Department Wise: Write a PHP script to accept the department name and display the employee details based on the selected department.

Here's a simplified example of how the PHP scripts might look:

<?php
// Connect to the database
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "employees";

$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
  die("Connection failed: " . $conn->connect_error);
}

// Function to calculate gross salary
function calculateGrossSalary($basicSalary) {
  $hra = 0.15 * $basicSalary;
  $otherAllowance = 0.1 * $basicSalary;
  $grossSalary = $basicSalary + $hra + $otherAllowance;
  return $grossSalary;
}

// Register Employee Details
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $empNumber = $_POST['Number'];
  $name = $_POST['name'];
  $department = $_POST['department'];
  $basicSalary $_POST['basicSalary'];
  
  // Calculate Gross Salary
  $grossSalary = calculateGrossSalary($basicSalary);
  
  // Store in database
  $sql = "INSERT INTO employee_details (empNumber, name, department, basicSalary, grossSalary) VALUES ('$empNumber', '$name', '$department', '$basicSalary', '$gross')";
  
  if ($conn->query($sql) === TRUE) {
    echo "Employee details stored successfully";
  } else {
    echo "Error: " . $sql . "<br>" . $conn->error;
  }
}

// Display Employee Details Department Wise
if (isset($_POST['departmentFilter'])) {
  $departmentFilter = $_POST['departmentFilter'];
  $sql = "SELECT * FROM employee_details WHERE department = '$departmentFilter'";
  $result = $conn->query($sql);
  
  if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
      echo "Emp Number: " . $row["empNumber"]. " - Name: " . $row["name"]. " - Department: " . $row["department"]. " - Basic Salary: " . $row["basicSalary"]. " - Gross Salary: " . $row["grossSalary"]. "<br>";
 }
  } else {
    echo "0 results";
  }
}

$conn->close();
?>

Note: This is a basic example for demonstration purposes. In a real application, you should consider security measures, validation, error handling, and database statements to prevent SQL injection.

(b) Given that server name is ‘localhost’, username is ‘mca@2ndyear’, write a PHP script to connect to a MySQL database semexamDB and fetch all the records from table students in it

Certainly! Below is an example of a PHP script to connect to a MySQL database named "semexamDB" with the provided credentials and fetch all the records from the "students" table:

<?php
$servername = "localhost";
$username = "mca@2ndyear";
$password = "your_password";
$dbname = "semexamDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// Fetch all records from the table
$sql = "SELECT * FROM students";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    // Output data of each row
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. " - Address: " . $row["address"]. "<br>";
    }
} else {
    echo "0 results";
}
$conn->close();
?>

Replace "your_password" with the actual password used to access the database. This script uses the mysqli object-oriented approach for database connectivity and querying. Also, ensure the provided MySQL user has the required permissions to access the "semexamDB" database and the "students" table.

Remember to handle errors and consider security measures, such as input validation and error handling, depending on the specific use case.

(c) Write a function in PHP called inside_out() that will accept an array and return it with its innermost elements swapped with its outer most elements. For example, the call inside_out(array("Let", "us", "see", "if", "it", "works")) would result in: ("see", "us", "Let", "works", "it", "if"). The array should only be altered if it has an even number of elements.

Certainly! Below is a PHP function called inside_out() that accepts an array and returns it with its innermost elements swapped with its outermost elements. The function ensures that the array is only altered if it has an even number of elements:

function inside_out($arr) {
    $length = count($arr);
    if($length % 2 == 0) {
        $firstHalf = array_slice($arr, 0, $length / 2);
        $secondHalf = array_slice($arr, $length / 2);
        $arr = array_merge(array_reverse($secondHalf), array_reverse($firstHalf));
    }
    return $arr;
}

// Test the function
$inputArray = array("Let", "us", "see", "if", "it", "works");
$outputArray = inside_out($inputArray);
print_routputArray);

In the example provided, the function inside_out() first checks if the length of the input array is even. If so, it splits the array into two halves and then reverses each half before merging them back together. If the input array has an odd number of elements, it will remain unaltered.

You can test this function by calling it with different arrays to verify its functionality.

Write a PHP file that can be added to other PHP files using the include or require functions. This file should:  Make a connection to a MySQL database, and log in with valid credentials. The connection resource should be stored in a variable with an appropriate name.  Create a database CAC_MCA if it does not exist.  Select the CAC_MCA database.  Create a table STUDENT2ndY with the following fields: o USERNAME VARCHAR(100) o PASSWORD HASH CHAR(40) o PHONE VARCHAR(10)  The USERNAME field should be designated as UNIQUE. If any of these operations cause an error, stop execution and print the error message.

Certainly! Below is an example of a PHP file that can be included in other PHP files using the include or require functions. This file:

Makes a connection to a MySQL database using valid credentials.
Creates a database named "CAC_MCA" if it does not exist.
Selects the "CAC_MCA" database.
Creates a table "STUDENT2ndY" with the specified fields.

<?php
// MySQL database credentials
$servername = "localhost";
$username = "your_username";
$password = "your_password";

// Create connection
$conn = new mysqli($servername, $username, $password);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// Create database CAC_MCA if it does not exist
$sqlCreateDB = "CREATE DATABASE IF NOT EXISTS CAC_MCA";
if ($conn->query($sqlCreateDB) === FALSE) {
    die("Error creating database: " . $conn->error);
}

// Select CAC_MCA database
$conn->select_db("CAC_MCA");

// Create table STUDENT2ndY
CreateTable = "CREATE TABLE IF NOT EXISTS STUDENT2ndY (
    USERNAME VARCHAR(100) UNIQUE,
    PASSWORD CHAR(40),
    PHONE(10)
)";
if ($conn->query($sqlCreateTable) === FALSE) {
    die("Error creating table: " . $conn->error);
}

echo "Database and table creation successful";

// Close connection
$conn->close();
?>

Replace "your_username" and "your_password" with the actual MySQL credentials required to connect to the database.

When including this file in other PHP scripts, it will execute the database and table creation operations and print the appropriate error messages if any operation fails.

(a) Create the pages for fruits and vegetables, write the program to display the selected item in separate page using cookies

Certainly! Below is an example of how you can create a simple PHP program to display pages for fruits and vegetables and write the program to display the selected item in a separate page using cookies.

index.php:

<!DOCTYPE html>
<html>
<head>
    <title>Fruits and Vegetables</title>
</head>
<body>
    <h2>Select an item:</h2>
    <ul>
        <li><a href="select_item.php?type=fruit&item=apple">Apple</a></li>
        <li><a href="select_item.php?type=fruit&item=banana">Banana</a></li>
        <li><a href="select_item.php?type=vegetable&item=carrot">Carrot</a></li>
        <li><a href="select_item.php?type=vegetable&item=cucumber">Cucumber</a></li>
    </ul>
</body>
</html>

select_item.php:

<?php
// Check if type and item are set
if(isset($_GET['type']) && isset($_GET['item'])) {
    $type = $_GET['type'];
    $item = $_GET['item'];

    // Set the selected item in a cookie
    setcookie('selected_item', "$type: $", time() + (86400 * 30), "/");
}

// Redirect to display_selected_item.php
header("Location: display_selected_item.php");
?>

display_selected_item.php:

<?php
// Retrieve the selected item from the cookie
if(isset($_COOKIE['selected_item'])) {
    $selectedItem = $_COOKIE['selected_item'];
    echo "You selected: " . $selectedItem;
} else {
    echo "No item selected";
}
?>

In this example, the index.php file contains links to select fruit or vegetable items, which lead to the select_item.php page. This page sets a cookie with the selected item and then immediately redirects to the display_selected_item.php page. The display_selected_item.php page retrieves the selected item from the cookie and displays it.

This simple example demonstrates how you can use cookies to track and display the selected item in a separate page. Remember to handle security considerations and validate user input appropriately in a production environment.

(b) What is Denial of Service? How can one generate such attack? Write down the security solutions to avoid such attacks. short easy ans in points

Denial of Service (DoS) Attack:

Denial of Service (DoS) is a cyber attack that aims to make a network resource (e.g., website, application) unavailable to its intended users.
This is accomplished by overwhelming the target with a flood of illegitimate requests, causing it to become slow or unresponsive.

Generating a DoS Attack:

DoS attacks can be generated using various methods, including:
1. Network flood attacks (e.g., ICMP flood, SYN flood)
2. Application-level attacks (e.g., HTTP flood, Slowloris)
3. Distributed Denial of Service (DDoS) attacks using botnets or multiple compromised systems.

Security Solutions:

Implementing these security measures can help avoid and mitigate DoS attacks:
1. Use firewalls and intrusion prevention systems to filter and block malicious traffic.
2. Employ rate limiting and traffic shaping to control the volume of incoming requests.
3. Utilize content delivery networks (CDNs) to distribute traffic and absorb DDoS attacks.
4. Regularly update and patch network devices and servers to protect against known vulnerabilities.
5. Deploy DoS protection services and tools that can detect and mitigate attacks in real-time.

(b) Explain the following global variable with a suitable example  $_SERVER,  $_FILES,  $_COOKIE,  $_SESSION. (c) Why $_REQUEST variable is used?

Explanation of Global Variables:

$_SERVER:
- to access information about the server and the execution environment.
- Example:
```
echo $_SERVER['HTTP_HOST']; // Outputs the host name from the request
```

$_FILES:

Holds information about file uploads via HTTP POST.

Example:

$uploadedFile = $_FILES['fileToUpload']['name']; // Accesses the name of the uploaded file

$_COOKIE:

Used to access cookies sent by the client to the server.

Example:

$userCookie = $_COOKIE['username']; // Retrieves the value of the 'username' cookie

$_SESSION:

Stores and retrieves session variables across multiple pages.

Example:

$_SESSION['user_id'] = 123; // Sets the user_id session variable to 123
$userId = $_SESSION['user_id']; // Retrieves the value of the user_id session variable


(c) Purpose of $_REQUEST Variable:
  - The $_REQUEST variable is used to collect data submitted from HTML forms using the HTTP POST or GET method.
  - It allows for the retrieval of data from both the $_POST and $_GET arrays, making it suitable for handling form data in a flexible manner.
  - Example:
    ```php
    $username = $_REQUEST['username']; // Retrieves the value of the 'username' field submitted via a form
    ```
  
  The use of $_REQUEST is convenient when the type of form submission (POST or GET) is not always predictable, and when the script needs to handle both types of requests uniformly.