The path of the scene that the user has currently open (Will be an empty string if no scene is currently open). (Read Only)
All paths are relative to the project folder. Like: "Assets/MyScenes/MyScene.unity".
// saves the current scene into a new temporary scene.
import UnityEditor;
@MenuItem ("Example/Save temp Scene %s")
static function SaveTempScene() {
var path : String [] = EditorApplication.currentScene.Split(char.Parse("/"));
path[path.Length -1] = "Temp_" + path[path.Length-1];
EditorApplication.SaveScene(String.Join("/",path));
}