Tutorial by Examples: f

A classic use of here documents is to create a file by typing its content: cat > fruits.txt << EOF apple orange lemon EOF The here-document is the lines between the << EOF and EOF. This here document becomes the input of the cat command. The cat command simply outputs its in...

Bash • Here documents and here strings

Adding custom headers to your requests [e.g. for basic auth]

If you need to add custom headers to your volley requests, you can't do this after initialisation, as the headers are saved in a private variable. Instead, you need to override the getHeaders() method of Request.class as such: new JsonObjectRequest(REQUEST_METHOD, REQUEST_URL, REQUEST_BODY, RESP_L...

Android • Volley

To find out who changed a file

// Shows the author and commit per line of specified file git blame test.c // Shows the author email and commit per line of specified git blame -e test.c file // Limits the selection of lines by specified range git blame -L 1,10 test.c

Git • Blaming

Set the URL namespace for a reusable app (Django 1.9+)

Configure your app's URLconf to automatically use a URL namespace by setting the app_name attribute: # In <myapp>/urls.py from django.conf.urls import url from .views import overview app_name = 'myapp' urlpatterns = [ url(r'^$', overview, name='overview'), ] This will set t...

Django • URL routing

Find Data in MongoDB Using Mongoose, Express.js Routes and $text Operator

Setup First, install the necessary packages with: npm install express cors mongoose Code Then, add dependencies to server.js, create the database schema and the name of the collection, create an Express.js server, and connect to MongoDB: var express = require('express'); var cors = require('...

Node.js • Mongoose Library

$this, self and static plus the singleton

Use $this to refer to the current object. Use self to refer to the current class. In other words, use $this->member for non-static members, use self::$member for static members. In the example below, sayHello() and sayGoodbye() are using self and $this difference can be observed here. cl...

PHP • Classes and Objects

Factorial calculation

The factorial of a number (denoted with !, as for instance 9!) is the multiplication of that number with the factorial of one lower. So, for instance, 9! = 9 x 8! = 9 x 8 x 7! = 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1. So in code that becomes, using recursion: long Factorial(long x) { if (x < 1...

C# Language • Recursion

Create (and write to a) known, persistant temporary file

You can create temporary files which has a visible name on the file system which can be accessed via the name property. The file can, on unix systems, be configured to delete on closure (set by delete param, default is True) or can be reopened later. The following will create and open a named temp...

Python Language • tempfile NamedTemporaryFile

Initializing an array filled with a repeated non-default value

As we know we can declare an array with default values: int[] arr = new int[10]; This will create an array of 10 integers with each element of the array having value 0 (the default value of type int). To create an array initialized with a non-default value, we can use Enumerable.Repeat from the...

C# Language • Arrays

Tutorial by Examples: f

The future: packages

Create a file

Adding custom headers to your requests [e.g. for basic auth]

To find out who changed a file

Set the URL namespace for a reusable app (Django 1.9+)

Find Data in MongoDB Using Mongoose, Express.js Routes and $text Operator

$this, self and static plus the singleton

Factorial calculation

Create (and write to a) known, persistant temporary file

Initializing an array filled with a repeated non-default value

Blur Filters: feGaussianBlur with hard edges & 100% Opacity

Blur Filters: Box Blur

Blur Filters: Bokeh Blur (3 layers, clipped)

Shadow Filters: Basic Dropshadow

Shadow Filters: Inner Glow

Shadow Filters: Complex Dropshadow (Contoured, Noisy, Shaped)

Color Manipulation Filters: Basic Greyscale

Color Manipulation Filters: Greyscale (Green Channel Only)

Color Manipulation Filters: Monotone

Blur Filters: Focus Blur (Gaussian)