Event.command
var command: bool;
bool command;
command as bool
Description

Is Command/Windows key held down? (Read Only)

On Windows, this returns true if any Windows key is held down.
On Mac, this returns true if any Command key is held down.
	// Prints Command/Windows key was pressed depending the
	// platform this script is being run.
	function OnGUI() {
		var e : Event = Event.current;
		if (e.command) {
			if(Application.platform == RuntimePlatform.OSXEditor) {
				Debug.Log("Command key was pressed");
			} else if( Application.platform == RuntimePlatform.WindowsEditor) {
				Debug.Log("Windows Key was pressed!");			
			}
		}
	}
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void OnGUI() {
        Event e = Event.current;
        if (e.command)
            if (Application.platform == RuntimePlatform.OSXEditor)
                Debug.Log("Command key was pressed");
            else
                if (Application.platform == RuntimePlatform.WindowsEditor)
                    Debug.Log("Windows Key was pressed!");
                
        
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def OnGUI() as void:
		e as Event = Event.current
		if e.command:
			if Application.platform == RuntimePlatform.OSXEditor:
				Debug.Log('Command key was pressed')
			elif Application.platform == RuntimePlatform.WindowsEditor:
				Debug.Log('Windows Key was pressed!')