How do I allow my application to run only once

[tgy3300]

How to realize that the application is only allowed to run once, and when it runs again, the application is detected to be running and must be blocked

[ogoffart]

It depends on the programming language and platform.

Typically, you'd do that with a file, in which you'd write the process id. If that file exist and the process id is still running, you consider the app is running. You may need to use the lock feature from the file system to avoid race conditions.

There perhaps exist a crate that does that. A quick search give me https://docs.rs/single-instance/ but i haven't tried.