habibutsu

define RUN_SCRIPT
import tarfile
import StringIO
import imp
import runpy

PKG_NAME = "some_module"

if __name__ == '__main__':
    tar_fd = StringIO.StringIO(PKG_DATA)

habibutsu

% For running can be used 'rabbitmqctl'
% Example:
%   sudo rabbitmqctl eval 'node().'

% Find process with the largest memory consumption
lists:sublist(
    lists:reverse(
        lists:sort([{process_info(Pid, memory), Pid, process_info(Pid)} || Pid <- processes()])), 1).

% get all vhosts

habibutsu

Overview

Simplest implementation of do-notation in Erlang without using parse-tranform

do

<<"16.0">> = pipeline:do(0, [
    fun(X) -> X+1 end,
    fun(X) -> X+3 end,

habibutsu

all: build

init:
	opam init -a
	opam pin add web-project . -n

get-deps:
	opam install --deps-only web-project

habibutsu

create or replace
function partition_insert_trigger() returns trigger
language 'plpgsql' as $$
declare
    column_name text := TG_ARGV[0];
    columnt_format text := TG_ARGV[1];
    column_value timestamp;
    table_name text;
    insert_stmt_tpl text := 'insert into %I select ($1).*';
    insert_stmt text;

habibutsu

List

Internal implementation

Erlang list is a singly linked list. Each item has a size of 2 Eterm: one for storing value, second for storing the pointer to next item.

When you append new element to the list:

• is created a new copy
• and then to the last element is set the pointer to list that needed to append

habibutsu

#OOOOOPS

Coding just for fun and relaxing

% erlc oooops.erl; erl -noshell -s oooops main -s init stop
-module(oooops).

habibutsu

-module(test).

-compile([export_all]).

-links([
    "https://github.com/efcasado/forms",
    "https://github.com/matwey/pybeam",
    "https://gist.github.com/kuenishi/3183043",
    "https://github.com/hypernumbers/LuvvieScript",
    "https://github.com/erlang/otp/blob/OTP-18.2/lib/compiler/src/genop.tab",

habibutsu

# check elapsed time after last modification

# not often than once at 15 minutes
if [ $(( $(date +%s) - $(stat --format %Y "some_file.txt") )) -gt 900 ]
then
    echo "old"
fi

habibutsu

// https://en.wikipedia.org/wiki/Mercator_projection
function MercatorProjection(){
    this.EARTH_RADIUS = 6378137 // WGS-84
    this.EARTH_HALF_CIRCUMFERENCE = Math.PI * this.EARTH_RADIUS // 20037508.342789244
    this.EARTH_METERS_PER_DEGREE = (Math.PI * this.EARTH_RADIUS) / 180   // 111319.49079327358
    this.RADIAN = Math.PI / 180
    this.DEGREE = 180 / Math.PI
}