Go helper to detect the global keypress events on OSX, it requires the root permissions enabled

go get github.com/GianlucaGuarini/OSXKeyboard

Call it once to start listening the global keyboard events

Subscribe to the keypress events receiving the letter pressed as string

Unsubscribe a specific callback to the keypress events

Build the following file from your go/src folder and then run it with sudo

package main

import (
  "fmt"
  "github.com/GianlucaGuarini/OSXKeyboard"
)

func main() {
  go OSXKeyboard.Listen()

  OSXKeyboard.Subscribe(func(letter string) {
    fmt.Println(letter)
  })

  select {} // block forever
}