What are some common pitfalls when using PHP to parse user input from a textarea?

One common pitfall when parsing user input from a textarea in PHP is not properly sanitizing the input, which can lead to security vulnerabilities such as SQL injection or cross-site scripting attacks. To solve this, always use functions like htmlspecialchars() or htmlentities() to escape special characters before displaying the input.

// Sanitize user input from a textarea
$user_input = $_POST['textarea_input'];
$sanitized_input = htmlspecialchars($user_input);

// Use $sanitized_input in your application
echo "Sanitized input: " . $sanitized_input;