一个低级的解决方案是使用 flock().

A low-level solution is to use flock().

每个实例都会在启动时尝试锁定一个文件，如果锁定失败，则另一个实例已经在运行.当你的程序退出时，Flocks 会自动释放，所以不用担心过时的锁.

Each instance would attempt to lock a file on startup, and if the lock fails then another instance is already running. Flocks are automagically released when your program exits, so no worries about stale locks.

请注意，无论您选择哪种解决方案，您都需要有意识地决定拥有多个实例"意味着什么.具体来说，如果多个用户同时运行您的应用，可以吗?

Note that whatever solution you choose, you need to make a conscious decision about what it means to have "multiple instances". Specifically, if multiple users are running your app at the same time, is that ok?