Tutorial by Examples: l

man <command> This will show the manual page for the specified command. For example, man ping will show: PING(8) BSD System Manager's Manual PING(8) NAME ping -- send ICMP ECHO_REQUEST packets to network hosts SYNOPSIS ping [-AaCDdfno...

$url = "https://api.dropboxapi.com/2/sharing/share_folder" $req = [System.Net.HttpWebRequest]::Create($url) $req.headers["Authorization"] = "Bearer <ACCESS_TOKEN>" $req.Method = "POST" $req.ContentType = "application/json" $enc = [system...

$url = "https://api.dropboxapi.com/2/users/get_current_account" $req = [System.Net.HttpWebRequest]::Create($url) $req.headers["Authorization"] = "Bearer <ACCESS_TOKEN>" $req.Method = "POST" $res = $req.GetResponse() Write-Host "Response Sta...

int a; printf("%d", a); The variable a is an int with automatic storage duration. The example code above is trying to print the value of an uninitialized variable (a was never initialized). Automatic variables which are not initialized have indeterminate values; accessing these can le...

Start by installing the PayPal Node module from NPM npm install paypal-rest-sdk In your application file, add in the configuration information for the SDK var paypal = require('paypal-rest-sdk'); var client_id = 'YOUR CLIENT ID'; var secret = 'YOUR SECRET'; paypal.configure({ 'mode'...

Consider the below list comprehension: >>> def f(x): ... import time ... time.sleep(.1) # Simulate expensive function ... return x**2 >>> [f(x) for x in range(1000) if f(x) > 10] [16, 25, 36, ...] This results in two calls to f(x) for 1,000 values of...

This code creates a sticky footer. When the content doesn't reach the end of the viewport, the footer sticks to the bottom of the viewport. When the content extends past the bottom of the viewport, the footer is also pushed out of the viewport. View Result HTML: <div class="header"&gt...

HTML: <div class="container"> <img src="http://lorempixel.com/400/200" /> </div> CSS: html, body, .container { height: 100%; } .container { display: flex; justify-content: center; /* horizontal center */ } img { align-self: center; /...

Defining a new protocol: @protocol NewProtocol - (void)protocolMethod:(id)argument; - (id)anotherMethod; @end

Browse to File > New > Project to bring you up the New Project dialog. Navigate to Visual C# > iOS > iPhone and select Single View App: Give your app a Name and press OK to create your project. Select the Mac Agent icon from the toolbar, as illustrated below: Select the Mac tha...

In this example, we're going to set up an Express server integration to display how to process a payment with PayPal, using the PayPal Node SDK. We will use a static JSON structure for the payment details for the sake of brevity. There are three general steps that we will follow when building out t...

git ls-remote is one unique command allowing you to query a remote repo without having to clone/fetch it first. It will list refs/heads and refs/tags of said remote repo. You will see sometimes refs/tags/v0.1.6 and refs/tags/v0.1.6^{}: the ^{} to list the dereferenced annotated tag (ie the commit ...

The !important declaration is used to override the usual specificity in a style sheet by giving a higher priority to a rule. Its usage is: property : value !important; #mydiv { font-weight: bold !important; /* This property won't be overridden by the ...

Data Manipulation Language (DML for short) includes operations such as INSERT, UPDATE and DELETE: -- Create a table HelloWorld CREATE TABLE HelloWorld ( Id INT IDENTITY, Description VARCHAR(1000) ) -- DML Operation INSERT, inserting a row into the table INSERT INTO HelloWorld (D...

do './config.pl'; This will read in the contents of the config.pl file and execute it. (See also: perldoc -f do.) N.B.: Avoid do unless golfing or something as there is no error checking. For including library modules, use require or use.

require Exporter; This will ensure that the Exporter module is loaded at runtime if it hasn't already been imported. (See also: perldoc -f require.) N.B.: Most users should use modules rather than require them. Unlike use, require does not call the module's import method and is executed at runti...

use Cwd; This will import the Cwd module at compile time and import its default symbols, i.e. make some of the module's variables and functions available to the code using it. (See also: perldoc -f use.) Generally this is will do the right thing. Sometimes, however, you will want to control whic...

Double click on the Main.Storyboard file. Set View As to iPhone 6: Drag a label and a button from the Toolbox to the design surface so that it looks like the image below: In the Properties pad, give the label and button the following properties: nothingNameTitleLabellblClicks[blank]Buttoncli...

When multi-line (?m) modifier is turned off, ^ matches only the input string's beginning: For the regex ^He The following input strings match: Hedgehog\nFirst line\nLast line Help me, please He And the following input strings do not match: First line\nHedgehog\nLast line IHedgehog ...

Signal numbers can be synchronous (like SIGSEGV – segmentation fault) when they are triggered by a malfunctioning of the program itself or asynchronous (like SIGINT - interactive attention) when they are initiated from outside the program, e.g by a keypress as Cntrl-C. The signal() function is part...