I would like to disallow some characters in the filenames of uploaded files.

For example, I want the file uploader to return a validation error if the file name contains any of the following characters: ; ‘ # @ | “ or if it contains php at the beggining of the file name or if it contains .php anywhere in the file name. Ideally, I would also like to lowercase the filenames and replace all diacritics with their clean counterparts.

Is there any way to achieve that? I am not asking for a plugin improvement. I am willing to modify the plugin and update my modifications through plugin updates. I would really appreciate an example.

Thank you.