Are there any best practices for handling user agent information in PHP applications?

When handling user agent information in PHP applications, it is important to sanitize and validate the data to prevent security vulnerabilities such as SQL injection or cross-site scripting attacks. One best practice is to use PHP's built-in functions like filter_input() with the FILTER_SANITIZE_STRING filter to clean the user agent string before using it in your application.

$userAgent = filter_input(INPUT_SERVER, 'HTTP_USER_AGENT', FILTER_SANITIZE_STRING);