UA3MQJ

‽Erlang/OTP 19 [erts-8.3] [64-bit] [smp:8:8] [async-threads:10]

Interactive Elixir (1.4.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> c("tst_gen.ex")
[TstGen]
iex(2)> 
nil
iex(3)> {:ok, pid} = TstGen.start_link
{:ok, #PID<0.88.0>}
iex(4)> 

UA3MQJ

iex(4)>
18:04:13.683 [error] GenServer #PID<0.355.0> terminating
** (stop) %DBConnection.ConnectionError{message: "tcp async recv: closed"}
Last message: {:tcp_closed, #Port<0.6368>}
State: %Postgrex.Notifications{listener_channels: %{"event" => %{#Reference<0.2125033689.3245080577.170420> => #PID<0.354.0>}}, listeners: %{#Reference<0.2125033689.3245080577.170420> => {"event", #PID<0.354.0>}}, parameters: nil, protocol: %Postgrex.Protocol{buffer: :active_once, connection_id: 30, connection_key: -507502396, null: nil, parameters: #Reference<0.2125033689.3245080577.170419>, peer: {{127, 0, 0, 1}, 5432}, postgres: :idle, queries: nil, sock: {:gen_tcp, #Port<0.6368>}, timeout: 15000, transactions: :naive, types: nil}}

18:04:13.683 [error] GenServer #PID<0.758.0> terminating
** (stop) %DBConnection.ConnectionError{message: "tcp recv: closed"}
Last message: nil
State: [types: Postgrex.DefaultTypes, database: "postgres", username: "postgres", password: "password", hostname: "127.0.0.1", port: 5432]

UA3MQJ

https://github.com/bryanjos/joken - A JSON Web Token (JWT) Library

1. Закодировать JWT - подпись секретным текстовым ключем "my_secret_key"

  token = %{user_id: 123}
  |> Joken.token()
  |> Joken.with_signer(Joken.hs256("my_secret_key"))
  |> Joken.sign()
  |> Joken.get_compact()

UA3MQJ

Сделал модуль

defmodule Tm do
  def test(x) do
    x + 1
  end
end

запуск ноды iex --sname ui
второй ноды на том же хосте iex --sname ui2

UA3MQJ

$ cat test.ex
defmodule Test do
  def test_case(foo) do
    case foo do
      :bar -> true
      :buz -> false
    end
  end

  def test_cond(foo) do

UA3MQJ

Erlang and Named Pipes

The intention of this post is to provide a solution (with examples) to a somewhat uncommon issue in Erlang. I hate searching for answers to the same problems over and over, and I had a hard time finding answers to this particular problem, so I wrote it all down once I figured it out. If one day you decide to read and write data through fifo's (named pipes) and then decide you want to read or write the other end of the pipe from Erlang, this post is for you.

The Problem

I wanted to read and write to a fifo from a C/C++ app and have an Erlang app communicate over the other end of that fifo. Put simply, Erlang doesn't really support what I was trying to do. You cannot just file:open/2 a fifo, or any special device for that matter, in Erlang and expect it to work. This is documented in Erlang's FAQ.

The Solution! ... ???

UA3MQJ

mnesia
https://stackoverflow.com/questions/421501/what-is-the-storage-capacity-of-a-mnesia-database?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa
http://igorrs.blogspot.ru/2010/05/mnesia-one-year-later.html
http://igorrs.blogspot.ru/2010/05/mnesia-one-year-later-part-2.html
http://igorrs.blogspot.ru/2010/05/mnesia-one-year-later-part-3.html
http://igorrs.blogspot.com/2009/11/consistent-hashing-for-mnesia-fragments.html
http://igorrs.blogspot.com/2009/11/consistent-hashing-for-mnesia-fragments_19.html
https://streamhacker.com/2008/12/10/how-to-eliminate-mnesia-overload-events/
http://noss.github.io/2009/04/04/mnesia-sucks-not.html
http://erlang.org/doc/apps/mnesia/mnesia.pdf

UA3MQJ

defmodule Benum do
  defimpl Enumerable, for: BitString do
    def count(collection) when is_binary(collection) do
      {:ok, Enum.reduce(collection, 0, fn v, acc -> acc + 1 end)}
    end
    def count(collection) do
      {:error, __MODULE__}
    end
    def member?(collection, value) when is_binary(collection) do
      {:ok, Enum.any?(collection, fn v -> value == v end)}

UA3MQJ

mkdir 'Осваиваем Zynq'
cd 'Осваиваем Zynq'
youtube-dl -f best -ciw -o "%(title)s.%(ext)s" -i PLWMg96mLREOekNVh8-3U5JZv2NTCLMbP5
cd ..

mkdir 'Boards review'
cd 'Boards review'
youtube-dl -f best -ciw -o "%(title)s.%(ext)s" -i PLWMg96mLREOcCO5xT3gnr111e-6gKAc-E
cd ..