🔗 iex -S mix phx.server: what? how?

iex -S mix phx.server: it starts up my Phoenix dev server under Elixir’s interactive shell program, IEx, so I can call functions from my app and whatnot.

One day, it started to bug me unreasonably much that I didn’t really understand how this command causes that to happen. Perhaps culpable: a touch of delirium, downstream of the flu.

There were a lot of reasons for my mystification (i.e. a lot of basic things I hadn’t thought much about before), so below you’ll find, if you want to, ~2700 words about some things that happen and how. I don’t expect even one whole person to read the entirety. It’s not that kind of blog post.

There may be inaccuracies.