使用NSWorkspace launchApplicationAtURL启动应用程序后获得退出状态

I'm kind of new at Mac programming. I am porting a plugin to OSX. I need my application to launch a second app (which I do not control the source for) and then get its exit code. NSWorkspace launchApplicationAtURL works great to launch it with the needed arguments but I can't see how to get the exit code. Is there a way to get it after setting up notification for termination of the second app? I see tools for getting an exit code using NSTask instead. Should I be using that?I'm kind of new at Mac programming. I am portin