Fix My Computer, Mark! - PHP Script and Java Script, to see if a Person Visitng my site is Human 

Scripts

PHP Script and Java Script, to see if a Person Visitng my site is Human

To determine if a visitor to your site is human, you can implement a CAPTCHA system using either PHP or JavaScript. Below are examples of how to create a simple CAPTCHA system in both languages.

PHP CAPTCHA Example

1. Create a CAPTCHA Image:

<?php
session_start();

// Generate a random string
$captcha_code = substr(md5(uniqid(mt_rand(), true)), 0, 6);
$_SESSION['captcha'] = $captcha_code;

// Create an image
$image = imagecreatetruecolor(100, 30);

// Set background and text color
$bg_color = imagecolorallocate($image, 255, 255, 255);
$text_color = imagecolorallocate($image, 0, 0, 0);

// Fill the background
imagefilledrectangle($image, 0, 0, 100, 30, $bg_color);

// Add the text
imagettftext($image, 20, 0, 10, 25, $text_color, 'path/to/font.ttf', $captcha_code);

// Output the image
header('Content-type: image/png');
imagepng($image);

// Clean up
imagedestroy($image);
?>

 

2. Create a Form to Display CAPTCHA:

<!DOCTYPE html>
<html>
<head>
    <title>CAPTCHA Example</title>
</head>
<body>
    <form action="verify.php" method="post">
        <p><img src="/captcha.php" alt="CAPTCHA Image"></p>
        <p><input type="text" name="captcha" placeholder="Enter CAPTCHA"></p>
        <p><input type="submit" value="Submit"></p>
    </form>
</body>
</html>

 

3. Verify CAPTCHA in PHP:

<?php
session_start();

if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    if ($_POST['captcha'] == $_SESSION['captcha']) {
        echo 'CAPTCHA verification successful!';
    } else {
        echo 'CAPTCHA verification failed!';
    }
}
?>

 

JavaScript CAPTCHA Example

1. HTML and JavaScript for CAPTCHA:

<!DOCTYPE html>
<html>
<head>
    <title>JavaScript CAPTCHA Example</title>
    <script>
        function generateCaptcha() {
            const characters = 'ABCDEFxbLFFJR8Y8S54LX8h7uSMDsb7EeVmyApqrstuvwxyz0123456789';
            let captcha = '';
            for (let i = 0; i < 6; i++) {
                captcha += characters.charAt(Math.floor(Math.random() * characters.length));
            }
            document.getElementById('captcha').innerHTML = captcha;
            document.getElementById('captcha_value').value = captcha;
        }

        function validateCaptcha() {
            const input = document.getElementById('captcha_input').value;
            const captcha = document.getElementById('captcha_value').value;
            if (input === captcha) {
                alert('CAPTCHA verification successful!');
            } else {
                alert('CAPTCHA verification failed!');
                generateCaptcha();
            }
            return false; // Prevent form submission for demonstration
        }
    </script>
</head>
<body onload="generateCaptcha()">
    <form onsubmit="return validateCaptcha()">
        <p id="captcha" style="font-size: 24px; font-weight: bold;"></p>
        <input type="hidden" id="captcha_value">
        <p><input type="text" id="captcha_input" placeholder="Enter CAPTCHA"></p>
        <p><input type="submit" value="Submit"></p>
    </form>
</body>
</html>

 

Both of these examples create a basic CAPTCHA system to differentiate between human users and bots. The PHP example uses server-side verification, while the JavaScript example uses client-side verification.

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