naifen

# list docker volumes
docker volume ls -f dangling=true

# rm all docker volumes
docker volume rm $(docker volume ls -qf dangling=true)

# stop all docker containers
docker stop $(docker ps -a -q)

naifen

After automatically updating Postgres to 10.0 via Homebrew, the pg_ctl start command didn't work.
The error was "The data directory was initialized by PostgreSQL version 9.6, which is not compatible with this version 10.0."

Database files have to be updated before starting the server, here are the steps that had to be followed:

# need to have both 9.6.x and latest 10.0 installed, and keep 10.0 as default
brew unlink postgresql
brew install [email protected]
brew unlink [email protected]
brew link postgresql

naifen

##
# .rubocop.yml

AllCops:
  TargetRubyVersion: 2.5
  Include:
    - 'config.ru'
    - 'Gemfile'
    - 'Guardfile'
    - 'Rakefile'

naifen

Check current driver version for a device, eg radeon

Get-WmiObject Win32_PnPSignedDriver| select devicename, driverversion | where {$_.devicename -like "radeon"}

naifen

def flatten_array(ary, result = [])
  raise 'Please pass an array as argument' unless ary.kind_of? Array

  # if an element in the given array is an array, recursively call flatten_array
  # on the element, otherwise push it into the result array
  ary.each do |ele|
    if ele.class == Array
      flatten_array(ele, result)
    else
      result << ele

naifen

React.js learning notes

React functional componenets and hooks

Use React memo API to prevent re-renders

In this example, every time you type something in the input field, the App component updates its state and triggers re-renders of the Count component. Use React memo in React Function Components to prevent a rerender when the incoming props of this component haven't changed:

import React, { useState, memo } from 'react';