What are some potential pitfalls when using PHP for CLI applications that require user input during runtime?

One potential pitfall when using PHP for CLI applications that require user input during runtime is not properly handling user input validation and sanitization, which can lead to security vulnerabilities such as code injection or unexpected behavior. To solve this issue, always validate and sanitize user input before using it in the application.

// Example of validating and sanitizing user input in a PHP CLI application

$handle = fopen("php://stdin","r");

echo "Enter your name: ";
$name = trim(fgets($handle));

// Validate and sanitize user input
if (!preg_match("/^[a-zA-Z ]+$/", $name)) {
    echo "Invalid input. Please enter a valid name.\n";
    exit;
}

echo "Hello, " . $name . "!\n";

fclose($handle);