spawn_ex1.ex

defmodule SpawnEx1 do
  import :timer, only: [sleep: 1]

  def greet(pid) do
    send pid, {:ok, "I'm alive"}
    exit(:dead)
  end

  def process_messages() do
    receive do
      {:ok, message} ->
        IO.puts "I got #{message}"
        process_messages()
    end
  end

  def run do
    me = self()
    spawn_link(SpawnEx1, :greet, [me])
    sleep 500
    process_messages()
  end
end

SpawnEx1.run

spawn_ex2.ex

defmodule SpawnEx2 do
  import :timer, only: [sleep: 1]

  def greet(pid) do
    send pid, {:ok, "I'm alive"}
    raise "I am dead"
  end

  def process_messages() do
    receive do
      {:ok, message} ->
        IO.puts "I got #{message}"
        process_messages()
    end
  end

  def run do
    me = self()
    spawn_link(SpawnEx2, :greet, [me])
    sleep 500
    process_messages()
  end
end

SpawnEx2.run