Before an iex
shell starts, it looks like a file .iex.exs
. It starts looking
at the current directory and if it doesn’t find one, it looks at a global one
at $HOME/.iex.exs
(usually ~/.iex.exs
). All the code inside the file is
loaded and added to the IEx
shell’s context, so all the modules imported,
aliases, required, and bindings from the file are accessible inside the shell.
In my .iex.exs
, I do the following:
- Enable
ansi
for better characters support. - Add
message_queue
to the prompt. I like playing with multipleiex
nodes and it’s handy to monitor inter-node communication. - Improve
history_limit
andinspect_limit
. - Make eval results
bright
. - Add
Plug
support. - Add
Phoenix
support and detectphoenix
apps. - Add
Ecto
support and detectecto
app. - Alias the main
ecto
Repo
module.
NOTE: As I do more elixir, I keep improving my .iex.exs
Here is my global iex.exs
file.
# Will be using `ANSI`
Application.put_env(:elixir, :ansi_enabled, true)
# Letting people know what iex.exs they are using
IO.puts IO.ANSI.magenta_background() <> IO.ANSI.bright() <> IO.ANSI.underline()
# <> IO.ANSI.blink_slow()
<> "Using global .iex.exs (located in ~/.iex.exs)" <> IO.ANSI.reset()
# Get queue length for the IEx process
# This is fun to see while playing with nodes
queue_length = fn ->
self()
|> Process.info()
|> Keyword.get(:message_queue_len)
end
prefix = IO.ANSI.light_black_background() <> IO.ANSI.green() <> "%prefix"
<> IO.ANSI.reset()
counter = IO.ANSI.light_black_background() <> IO.ANSI.green() <> "-%node-(%counter)"
<> IO.ANSI.reset()
info = IO.ANSI.light_blue() <> "✉ #{queue_length.()}" <> IO.ANSI.reset()
last = IO.ANSI.yellow() <> "➤➤➤" <> IO.ANSI.reset()
alive = IO.ANSI.bright() <> IO.ANSI.yellow() <> IO.ANSI.blink_rapid() <> "⚡"
<> IO.ANSI.reset()
default_prompt = prefix <> counter <> " | " <> info <> " | " <> last
alive_prompt = prefix <> counter <> " | " <> info <> " | " <> alive <> last
inspect_limit = 5_000
history_size = 100
eval_result = [:green, :bright]
eval_error = [:red, :bright]
eval_info = [:blue, :bright]
# Configuring IEx
IEx.configure [
inspect: [limit: inspect_limit],
history_size: history_size,
colors: [
eval_result: eval_result,
eval_error: eval_error,
eval_info: eval_info,
],
default_prompt: default_prompt,
alive_prompt: alive_prompt
]
# Phoenix Support
import_if_available Plug.Conn
import_if_available Phoenix.HTML
phoenix_app = :application.info()
|> Keyword.get(:running)
|> Enum.reject(fn {_x, y} ->
y == :undefined
end)
|> Enum.find(fn {x, _y} ->
x |> Atom.to_string() |> String.match?(~r{_web})
end)
# Check if phoenix app is found
case phoenix_app do
nil -> IO.puts "No Phoenix App found"
{app, _pid} ->
IO.puts "Phoenix app found: #{app}"
ecto_app = app
|> Atom.to_string()
|> (&Regex.split(~r{_web}, &1)).()
|> Enum.at(0)
|> String.to_atom()
exists = :application.info()
|> Keyword.get(:running)
|> Enum.reject(fn {_x, y} ->
y == :undefined
end)
|> Enum.map(fn {x, _y} -> x end)
|> Enum.member?(ecto_app)
# Check if Ecto app exists or running
case exists do
false -> IO.puts "Ecto app #{ecto_app} doesn't exist or isn't running"
true ->
IO.puts "Ecto app found: #{ecto_app}"
# Ecto Support
import_if_available Ecto.Query
import_if_available Ecto.Changeset
# Alias Repo
repo = ecto_app |> Application.get_env(:ecto_repos) |> Enum.at(0)
quote do
alias unquote(repo), as: Repo
end
end
end
Let me know if you have ways in which this can be further improved