If Elixir ever gets a magazine it should be called ctrl-GQ.

I’ll see myself out.

There are scenarios where CTRL-C twice could take down daemons running on a remote node. Not much harm if you are just messing around locally. However, if we are talking best practices, you’d probably want CTRL-G to bring up the User switch command menu, followed by q. Try h to see the options available.

I learned ctrl-g q from an Erlanger early in my Elixir career and taught it to my fingers.

Here’s another tip courtesy of the System module.

You know “that” error…?

** (RuntimeError) could not compile application: my_app.

You must restart your server after changing the following files:

• config/dev.exs

  (phoenix 1.7.12) lib/phoenix/code_reloader/server.ex:236: Phoenix.CodeReloader.Server.mix_compile_unless_stale_config/4

Just do as it says…

iex> System.restart()

It’ll recompile and reload everything for you.

The first CTRL-C gets you into the break menu which gives you a few diagnostic options. When you then press q or a and ENTER, or simply another CTRL-C you are effectively doing a System.halt(0) call.

CTRL-\ bypasses the break menu altogether and quits.

System.stop(0) is more graceful than System.halt(0). System.stop(0) signals :sigstop to the Erlang VM. It’s the same as calling :init.stop(0). From the documentation:

All applications are taken down smoothly, all code is unloaded, and all ports are closed before the system terminates by calling halt(Status).

System.halt(0) signals a :sigquit to the VM, which is equal to calling :erlang.halt(0). It abruptly shuts down everything (no apps are gracefully stopped or ports properly closed.)

You’ll notice that System.stop(0) takes a moment to shut down and returns an :ok atom if successful. System.halt(0) is essentially immediate.