What measures can be taken to prevent unauthorized access to file operations in PHP functions?

To prevent unauthorized access to file operations in PHP functions, it is important to validate user input and implement proper access control measures. This can include checking user permissions before allowing file operations to be executed, sanitizing input to prevent malicious file paths, and using secure file handling functions.

// Example of validating user permissions before allowing file operations
$userRole = getUserRole(); // Function to retrieve user role
if($userRole === 'admin'){
    // Allow file operations for admin users
    // Perform file operations here
} else {
    // Display an error message or redirect unauthorized users
    echo "Unauthorized access";
}