use of undeclared type 'NSFileHandle'

Hi,

am running swift 3.0.2 on Ubuntu.

when I run the following code

import Foundation

let file: NSFileHandle? = NSFileHandle(forReadingAtPath: "data.txt")

I get an error of

test.swift:274:11: error: use of undeclared type 'NSFileHandle'

let file: NSFileHandle? = NSFileHandle(forReadingAtPath: "data.txt")

^~~~~~~~~~~~

NSFileHandle is in the APIs for Foundation though is this true for the Foundation library on Linux?

What am I doing wrong?

Regards,

John