What are the recommended methods for handling character encoding discrepancies between HTML forms, PHP scripts, and database entries to prevent issues with special characters like Umlauts in file names?

Character encoding discrepancies can lead to issues with special characters like Umlauts in file names when data is passed between HTML forms, PHP scripts, and databases. To prevent these issues, it is recommended to ensure that all components are using the same character encoding, such as UTF-8. This can be achieved by setting the appropriate character encoding in the HTML form, using PHP functions like mb_convert_encoding() to handle encoding conversions in scripts, and ensuring that the database is configured to store data in the same encoding.

// Set UTF-8 encoding in HTML form
<form accept-charset="UTF-8">

// Convert encoding in PHP script
$filename = mb_convert_encoding($filename, 'UTF-8');

// Set UTF-8 encoding in database connection
$mysqli->set_charset("utf8");