Tutorial by Examples: an

Redirecting both STDOUT and STDERR

File descriptors like 0 and 1 are pointers. We change what file descriptors point to with redirection. >/dev/null means 1 points to /dev/null. First we point 1 (STDOUT) to /dev/null then point 2 (STDERR) to whatever 1 points to. # STDERR is redirect to STDOUT: redirected to /dev/null, # effect...

Bash • Redirection

Float an Image Within Text

The most basic use of a float is having text wrap around an image. The below code will produce two paragraphs and an image, with the second paragraph flowing around the image. Notice that it is always content after the floated element that flows around the floated element. HTML: <p>Lorem ips...

CSS • Floats

Event Bubbling and Capturing

Events fired on DOM elements don't just affect the element they're targeting. Any of the target's ancestors in the DOM may also have a chance to react to the event. Consider the following document: <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> </hea...

DOM • Events

Downloading a file with every error case handled using the SwiftyDropbox library

Dropbox.authorizedClient!.files.download(path: path, destination: destination).response { response, error in if let (metadata, url) = response { print("*** Download file ***") print("Downloaded file name: \(metadata.name)") print("Downloaded f...

Dropbox API • Downloading a file

Downloading a piece of a file via curl using Range Retrieval Requests

This downloads just a piece of a file, using Range Retrieval Requests, from the Dropbox API at the remote path /Homework/math/Prime_Numbers.txt to the local path Prime_Numbers.txt.partial in the current folder: curl -X GET https://content.dropboxapi.com/2/files/download \ --header "Auth...

Dropbox API • Downloading a file

Uploading a file from NSData with every error case handled using the SwiftyDropbox library

This uses the SwiftyDropbox library to upload a file from a NSData to the Dropbox account, using upload sessions for larger files, handling every error case: import UIKit import SwiftyDropbox class ViewController: UIViewController { // replace this made up data with the real data le...

Dropbox API • Uploading a file

Sharing a folder with every error case handled using the SwiftyDropbox library

This uses the SwiftyDropbox library to share a folder, handling every error case: Dropbox.authorizedClient!.sharing.shareFolder(path: "/folder_path").response { response, error in if let result = response { print("response: \(result)") } else if let callError ...

Dropbox API • Sharing a folder

Inviting a member to a shared folder with every error case handled using the SwiftyDropbox library

let toInvite = [Sharing.AddMember(member: Sharing.MemberSelector.Email("<EMAIL_ADDRESS_TO_INVITE>"))] Dropbox.authorizedClient!.sharing.addFolderMember(sharedFolderId: "<SHARED_FOLDER_ID>", members: toInvite).response { response, error in if (response != nil...

Dropbox API • Sharing a folder

Listing the root folder via curl in PHP and the cURL extension

<?php $parameters = array('path' => '','include_deleted' => true,'recursive' => true); $headers = array('Authorization: Bearer <ACCESS_TOKEN>', 'Content-Type: application/json'); $curlOptions = array( CURLOPT_HTTPHEADER => $headers, C...

Dropbox API • Listing a folder

Listing the root folder using the SwiftyDropbox library, distinguishing files and folders in the response

Dropbox.authorizedClient!.files.listFolder(path: "").response { response, error in print("*** List folder ***") if let result = response { print("Folder contents:") for entry in result.entries { print(entry.name) if ...

Dropbox API • Listing a folder

Attempting to list a non-existant folder using the SwiftyDropbox library, as an example of error handling

// List folder Dropbox.authorizedClient!.files.listFolder(path: "/nonexistantpath").response { response, error in print("*** List folder ***") if let result = response { print("Folder contents:") for entry in result.entries { pr...

Dropbox API • Listing a folder

Retrieving an existing shared link for a specific file using curl

curl -X POST https://api.dropboxapi.com/2/sharing/list_shared_links \ --header "Authorization: Bearer <ACCESS_TOKEN>" \ --header "Content-Type: application/json" \ --data "{\"path\": \"/test.txt\", \"direct_only\": true}&quo...

Dropbox API • Getting a shared link for a file or folder

Listing branches

Git provides multiple commands for listing branches. All commands use the function of git branch, which will provide a list of a certain branches, depending on which options are put on the command line. Git will if possible, indicate the currently selected branch with a star next to it. GoalCommand...

Git • Branching

Serializing and restoring class instances

You can use a custom toJSON method and reviver function to transmit instances of your own class in JSON. If an object has a toJSON method, its result will be serialized instead of the object itself. 6 function Car(color, speed) { this.color = color; this.speed = speed; } Car.prototype.to...

JavaScript • JSON

Converting between Blobs and ArrayBuffers

JavaScript has two primary ways to represent binary data in the browser. ArrayBuffers/TypedArrays contain mutable (though still fixed-length) binary data which you can directly manipulate. Blobs contain immutable binary data which can only be accessed through the asynchronous File interface. Conver...

JavaScript • Binary Data

Manipulating ArrayBuffers with DataViews

DataViews provide methods to read and write individual values from an ArrayBuffer, instead of viewing the entire thing as an array of a single type. Here we set two bytes individually then interpret them together as a 16-bit unsigned integer, first big-endian then little-endian. var buffer = new Ar...

JavaScript • Binary Data

Binding `this` and arguments

5.1 When you take a reference to a method (a property which is a function) in JavaScript, it usually doesn't remember the object it was originally attached to. If the method needs to refer to that object as this it won't be able to, and calling it will probably cause a crash. You can use the .bind...

JavaScript • Functions

Basic interpolation and multiline strings

Template literals are a special type of string literal that can be used instead of the standard '...' or "...". They are declared by quoting the string with backticks instead of the standard single or double quotes: `...`. Template literals can contain line breaks and arbitrary expression...

JavaScript • Template Literals

Basic inheritance

Inheritance in Python is based on similar ideas used in other object oriented languages like Java, C++ etc. A new class can be derived from an existing class as follows. class BaseClass(object): pass class DerivedClass(BaseClass): pass The BaseClass is the already existing (parent)...

Python Language • Classes

Class and instance variables

Instance variables are unique for each instance, while class variables are shared by all instances. class C: x = 2 # class variable def __init__(self, y): self.y = y # instance variable C.x # 2 C.y # AttributeError: type object 'C' has no attribute 'y' c1 = C(3) c1....

Python Language • Classes