Retrieve player's OS on "OnLogin"

[PureTryOut]

Is there anyway to retrieve the OS the player is using on the hook "OnLogin"?
I'm trying to create a plugin for a server with only Linux users, and I would like to keep Windows users (and OSX for that matter) out this way.

[NiLSPACE]

No, this isn't possible. We don't receive any information about the OS from the users.

[PureTryOut]

A shame, I guess the client would have to be changed for that right? Never mind then, thanks for your answer!