fixup

.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

.gitignore

@@ -0,0 +1,24 @@
+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Temporary files, for example, from tests.
+/tmp/
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+alter_proxy-*.tar
+

lib/alter_proxy.ex

@@ -0,0 +1,39 @@
+defmodule AlterProxy do
+  def start(port) do
+    # 監聽端口
+    {:ok, listen_socket} =
+      :gen_tcp.listen(port, [
+        :binary,
+        packet: :line,
+        reuseaddr: true,
+        active: false,
+        backlog: 100
+      ])
+
+    accept_loop(listen_socket)
+  end
+
+  defp accept_loop(listen_socket) do
+    {:ok, socket} = :gen_tcp.accept(listen_socket)
+
+    # 爲每個客戶端創建新進程處理
+    spawn(__MODULE__, :handle_client, [socket])
+
+    # 繼續等待下一個連接
+    accept_loop(listen_socket)
+  end
+
+  def handle_client(socket) do
+    # 接收數據
+    case :gen_tcp.recv(socket, 0) do
+      {:ok, data} ->
+        IO.puts("收到: #{data}")
+        :gen_tcp.send(socket, "Echo: #{data}")
+        # 繼續接收
+        handle_client(socket)
+
+      {:error, :closed} ->
+        IO.puts("客戶端斷開連接")
+    end
+  end
+end

lib/alter_proxy/application.ex

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+defmodule AlterProxy.Application do
+  # See https://hexdocs.pm/elixir/Application.html
+  # for more information on OTP Applications
+  @moduledoc false
+
+  use Application
+
+  @impl true
+  def start(_type, _args) do
+    children = [
+      # Starts a worker by calling: AlterProxy.Worker.start_link(arg)
+      # {AlterProxy.Worker, arg}
+    ]
+
+    # See https://hexdocs.pm/elixir/Supervisor.html
+    # for other strategies and supported options
+    opts = [strategy: :one_for_one, name: AlterProxy.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+end

mix.exs

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+defmodule AlterProxy.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :alter_proxy,
+      version: "0.1.0",
+      elixir: "~> 1.19",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger],
+      mod: {AlterProxy.Application, []}
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      # {:dep_from_hexpm, "~> 0.3.0"},
+      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
+    ]
+  end
+end

test/alter_proxy_test.exs

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+defmodule AlterProxyTest do
+  use ExUnit.Case
+  doctest AlterProxy
+
+  test "greets the world" do
+    assert AlterProxy.hello() == :world
+  end
+end

test/test_helper.exs

@@ -0,0 +1 @@
+ExUnit.start()