Exit terminates the application via os.Exit but waits for all exit handlers to complete before calling os.Exit.

Fatal is a replacement for log.Fatal which will trigger the closure of all registered exit handlers and waits for their completion and then call os.Exit(1).

Fatalf is a replacement for log.Fatalf and behaves like Fatal.

Listen registers an exit handler which is called on SIGINT/SIGKILL/SIGTERM or when Exit/Fatal/Fatalf is called.

Wait waits for all exit handlers to complete.