Tutorial by Examples: re

Remove a Docker network

docker network rm app-backend This command removes the user-defined app-backend network from the Docker host. All containers on the network not otherwise connected via another network will lose communication with other containers. It is not possible to remove the default bridge bridge network, th...

Docker • Docker network

Creating a data volume

docker run -d --name "mysql-1" -v "/var/lib/mysql" mysql This command creates a new container from the mysql image. It also creates a new data volume, which it then mounts in the container at /var/lib/mysql. This volume helps any data inside of it persist beyond the lifetime o...

Docker • Data Volumes and Data Containers

How to create a basic LAMP environment with default networking

docker-compose.yml version: '2' services: php: image: phpmyadmin/phpmyadmin links: - mysql:db depends_on: - mysql mysql: image: k0st/alpine-mariadb volumes: - ./data/mysql:/var/lib/mysql environment: - MYSQL_DATABASE=mydb ...

docker-compose • Docker-compose multi-container example with default network

RS - Record Separator

Used by awk to split the input into multiple records. For example: echo "a b c|d e f" | awk 'BEGIN {RS="|"} {print $0}' produces: a b c d e f By default, the record separator is the newline character. Similarly: echo "a b c|d e f" | awk 'BEGIN {RS="|&quo...

awk • Built-in Variables

Creating a named volume

docker volume create --name="myAwesomeApp" Using a named volume makes managing volumes much more human-readable. It is possible to create a named volume using the command specified above, but it's also possible to create a named volume inside of a docker run command using the -v or --vo...

Docker • Docker Data Volumes

Create a Docker machine

Using docker-machine is the best method to install Docker on a machine. It will automatically apply the best security settings available, including generating a unique pair of SSL certificates for mutual authentication and SSH keys. To create a local machine using Virtualbox: docker-machine create...

Docker • Docker Machine

Phone Number Recognition

Mobile platforms like iOS automatically recognize phone numbers and turn them into tel: links. While the feature is very practical, the system sometimes detects ISBN codes and other numbers as telephone numbers. For mobile Safari and some other WebKit-based mobile browsers to turn off automatic pho...

HTML • Meta Information

Increment/Decrement Numeric Properties

Numeric CSS properties can be incremented and decremented with the += and -= syntax, respectively, using the .css() method: // Increment using the += syntax $("#target-element").css("font-size", "+=10"); // You can also specify the unit to increment by $...

jQuery • CSS Manipulation

LOOP as an Expression

Unlike the loops in nearly every other programming language in use today, the LOOP in Common Lisp can be used as an expression: (let ((doubled (loop for x from 1 to 10 collect (* 2 x)))) doubled) ;; ==> (2 4 6 8 10 12 14 16 18 20) (loop for x from 1 to 10 sum x) ...

common-lisp • LOOP, a Common Lisp macro for iteration

Generating Date Range With Recursive CTE

Using a Recursive CTE, you can generate an inclusive range of dates: Declare @FromDate Date = '2014-04-21', @ToDate Date = '2014-05-02' ;With DateCte (Date) As ( Select @FromDate Union All Select DateAdd(Day, 1, Date) From DateCte Where Date < @T...

Microsoft SQL Server • Generating a range of dates

Recursive list processing with pattern matching

Here we demonstrate how to process lists recursively using OCaml's pattern matching syntax. let rec map f lst = match lst with | [] -> [] | hd::tl -> (f hd)::(map f tl) In this case, the pattern [] matches the empty list, while hd::tl matches any list that has at least one element...

OCaml • Pattern Matching

Test if cookies are enabled

If you want to make sure cookies are enabled before using them, you can use navigator.cookieEnabled: if (navigator.cookieEnabled === false) { alert("Error: cookies not enabled!"); } Note that on older browsers navigator.cookieEnabled may not exist and be undefined. In those case...

JavaScript • Cookies

Folder Recursion

Early Bound (with a reference to Microsoft Scripting Runtime) Sub EnumerateFilesAndFolders( _ FolderPath As String, _ Optional MaxDepth As Long = -1, _ Optional CurrentDepth As Long = 0, _ Optional Indentation As Long = 2) Dim FSO As Scriptin...

VBA • Recursion

Creating a Simple VB.NET WinForms Application using a Text Editor

Open a text editor (like Notepad), and type the code below: Imports System.ComponentModel Imports System.Drawing Imports System.Windows.Forms Namespace SampleApp Public Class MainForm : Inherits Form Private btnHello As Button ' The form's constructor: thi...

winforms • Getting started with winforms

rect (a path command)

context.rect(leftX, topY, width, height) Draws a rectangle given a top-left corner and a width & height. <!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid red; } </style> <script> window.onload...

html5-canvas • Path (Syntax only)

Creating a Future

import scala.concurrent.Future import scala.concurrent.ExecutionContext.Implicits.global object FutureDivider { def divide(a: Int, b: Int): Future[Int] = Future { // Note that this is integer division. a / b } } Quite simply, the divide method creates a Future tha...

Scala Language • Futures

Consuming a Successful Future

The easiest way to consume a successful Future-- or rather, get the value inside the Future-- is to use the map method. Suppose some code calls the divide method of the FutureDivider object from the "Creating a Future" example. What would the code need to look like to get the quotient of...

Scala Language • Futures

Consuming a Failed Future

Sometimes the computation in a Future can create an exception, which will cause the Future to fail. In the "Creating a Future" example, what if the calling code passed 55 and 0 to the divide method? It'd throw an ArithmeticException after trying to divide by zero, of course. How would t...

Scala Language • Futures

Putting the Future Together

The previous examples demonstrated the individual features of a Future, handling success and failure cases. Usually, however, both features are handled much more tersely. Here's the example, written in a neater and more realistic way: object Calculator { def calculateAndReport(a: Int, b: Int...

Scala Language • Futures

Recursive JOINs

Recursive joins are often used to obtain parent-child data. In SQL, they are implemented with recursive common table expressions, for example: WITH RECURSIVE MyDescendants AS ( SELECT Name FROM People WHERE Name = 'John Doe' UNION ALL SELECT People.Name FROM Peopl...

SQL • JOIN