Tutorial by Examples: nd

cat < file.txt Output is same as cat file.txt, but it reads the contents of the file from standard input instead of directly from the file. printf "first line\nSecond line\n" | cat -n The echo command before | outputs two lines. The cat command acts on the output to add line num...

The easiest way to get up and running is to install Git for Windows from this download page, and select "Use Git and optional Unix tools from the Windows Command Prompt" as in the screenshot below. After this, meteor admin get-machine <os-architecture> will work exactly as it does...

Bold Text To bold text, use the <strong> or <b> tags: <strong>Bold Text Here</strong> or <b>Bold Text Here</b> What’s the difference? Semantics. <strong> is used to indicate that the text is fundamentally or semantically important to the surrounding...

To offset text either upward or downward you can use the tags <sup> and <sub>. To create superscript: <sup>superscript here</sup> To create subscript: <sub>subscript here</sub>

Local variables are defined within a function, method, or closure: func printSomething() { let localString = "I'm local!" print(localString) } func printSomethingAgain() { print(localString) // error } Global variables are defined outside of a function, method, or c...

Output buffering allows you to store any textual content (Text, HTML) in a variable and send to the browser as one piece at the end of your script. By default, php sends your content as it interprets it. <?php // Turn on output buffering ob_start(); // Print some output to the buffer (via...

A block that performs addition of two double precision numbers, assigned to variable addition: double (^addition)(double, double) = ^double(double first, double second){ return first + second; }; The block can be subsequently called like so: double result = addition(1.0, 2.0); // result =...

A module can be "imported", or otherwise "required" by the require() function. For example, to load the http module that ships with Node.js, the following can be used: const http = require('http'); Aside from modules that are shipped with the runtime, you can also require mod...

Considering the following users table: idusername1User12User23User34User45User5 In order to constrain the number of rows in the result set of a SELECT query, the LIMIT clause can be used together with one or two positive integers as arguments (zero included). LIMIT clause with one argument When ...

One use case for assertion is precondition and postcondition. This can be very useful to maintain invariant and design by contract. For a example a length is always zero or positive so this function must return a zero or positive value. #include <stdio.h> /* Uncomment to disable `assert()`...

When an exception object is created (i.e. when you new it), the Throwable constructor captures information about the context in which the exception was created. Later on, this information can be output in the form of a stacktrace, which can be used to help diagnose the problem that caused the excep...

For Android, here is the code we recommend for generating, persisting and retrieving a UUID. There is not constructor that accepts the UUID as a parameter, so you must instantiate Pubnub object first then use the setter to provide the UUID. // creating the Pubnub connection object with minimal args...

To find files, use the -type f flag $ find . -type f To find directories, use the -type d flag $ find . -type d To find block devices, use the -type b flag $ find /dev -type b To find symlinks, use the -type l flag $ find . -type l

Sometimes we will need to run commands against a lot of files. This can be done using xargs. find . -type d -print | xargs -r chmod 770 The above command will recursively find all directories (-type d) relative to . (which is your current working directory), and execute chmod 770 on them. The -...

On an ext filesystem, each file has a stored Access, Modification, and (Status) Change time associated with it - to view this information you can use stat myFile.txt; using flags within find, we can search for files that were modified within a certain time range. To find files that have been modifi...

Tuples can be decomposed into individual variables with the following syntax: let myTuple = (name: "Some Name", age: 26) let (first, second) = myTuple print(first) // "Some Name" print(second) // 26 This syntax can be used regardless of if the tuple has unnamed properti...

In this example we're going to look at testing webhook notifications in sandbox, using ngrok to provide a tunnel for our Node HTTP listener, running on localhost, to the internet. For this example, we're going to be using Node to set up notification webhooks for payment events (such as a payment bei...

Since the new line separator varies from platform to platform (e.g. \n on Unix-like systems or \r\n on Windows) it is often necessary to have a platform-independent way of accessing it. In Java it can be retrieved from a system property: System.getProperty("line.separator") Java SE 7 ...

You can add an image to your message using the parameter media_url. # Download the twilio-python library from http://twilio.com/docs/libraries from twilio.rest import TwilioRestClient # Find these values at https://twilio.com/user/account account_sid = "ACXXXXXXXXXXXXXXXXX" auth_to...

To send your first SMS with Twilio and Python you'll just need the Twilio-Python helper library to get started. # Download the twilio-python library from http://twilio.com/docs/libraries from twilio.rest import TwilioRestClient # Find these values at https://twilio.com/user/account account_si...