Tutorial by Examples: e

Indent an entire file using built-in indentention engine

In command mode(Esc) enter :gg=G to use Vim's built-in indention engine. Command PartDescriptionggstart of file=indent (when equalprg is empty)Gend of file You can set equalprg in your .vimrc to use a more sophisticated auto-formatting tool. For example, to use clang-format for C/C++ put the foll...

vim • Indentation

Processing long running queries with Node

Since Node is single-threaded, there is a need of workaround if it comes to a long-running calculations. Note: this is "ready to run" example. Just, don't forget to get jQuery and install the required modules. Main logic of this example: Client sends request to the server. Server sta...

Node.js • Performance challenges

The importance of preallocation

Arrays in MATLAB are held as continuous blocks in memory, allocated and released automatically by MATLAB. MATLAB hides memory management operations such as resizing of an array behind easy to use syntax: a = 1:4 a = 1 2 3 4 a(5) = 10 % or alternatively a = [a, 10] a = ...

MATLAB Language • Performance and Benchmarking

Value From App.Config

<asp:Literal runat="server" text="<%$ AppSettings:MyAppSettingName %>"/>

ASP.NET • Expressions

Evaluated Expression

ASP.NET • Expressions

Code Block Within ASP Markup

ASP.NET • Expressions

Word Count Example in Hive

Docs file (Input File) Mary had a little lamb its fleece was white as snow and everywhere that Mary went the lamb was sure to go. Hive Query CREATE TABLE FILES (line STRING); LOAD DATA INPATH 'docs' OVERWRITE INTO TABLE FILES; CREATE TABLE word_counts AS SELECT word, count(1) AS count F...

hive • Getting started with hive

Hello world!

The example is taken from threejs website. You may want to download three.js and change the script source below. There are many more advanced examples under this link. HTML: <html> <head> <meta charset=utf-8> <title>My first Three.js app</title> <...

three.js • Getting started with three.js

Reading files: foreach vs. while

When reading a potentially large file, a while loop has a significant memory advantage over foreach. The following will read the file record by record (by default, "record" means "a line", as specified by $/), assigning each one to $_ as it is read: while(<$fh>) { pri...

Perl Language • Memory usage optimization

Processing long lists

If you have a list in memory already, the straightforward and usually sufficient way to process it is a simple foreach loop: foreach my $item (@items) { ... } This is fine e.g. for the common case of doing some processing on $item and then writing it out to a file without keeping the data ...

Perl Language • Memory usage optimization

Installation on Amazon Linux from git repo

Amazon Linux is a RHEL variant, so the Red Hat instructions should work for the most part. There is, however, at least one discrepancy. There was an instance where the python27-devel package, as opposed to python-devel, was explicitly necessary. Here, we will install from source. sudo yum -y upd...

ansible • Installation

Creating an Connection to other Excel Files to query

There are many fine ways to get this done, which others have already suggested. Following along the "get Excel data via SQL track", here are some pointers. Excel has the "Data Connection Wizard" which allows you to import or link from another data source or even within the very ...

excel • Create Connection to other Excel Files

Creating Requests

php artisan make:request StoreUserRequest php artisan make:request UpdateUserRequest Note: You can also consider using names like StoreUser or UpdateUser (without Request appendix) since your FormRequests are placed in folder app/Http/Requests/.

Laravel • Form Request(s)

Verifying a Returned Value

[Test] public void Calculator_Add_ReturnsSumOfTwoNumbers() { Calculator calculatorUnderTest = new Calculator(); double result = calculatorUnderTest.Add(2, 3); Assert.AreEqual(5, result); }

unit-testing • Assertion Types

State Based Testing

Given this simple class, we can test that the ShaveHead method is working correctly by asserting state of the HairLength variable is set to zero after the ShaveHead method is called. public class Person { public string Name; public int HairLength; public Person(string name, in...

unit-testing • Assertion Types

Verifying an Exception is Thrown

Sometimes it is necessary to assert when an exception is thrown. Different unit testing frameworks have different conventions for asserting that an exception was thrown, (like NUnit's Assert.Throws method). This example does not use any framework specific methods, just built in exception handling. ...

unit-testing • Assertion Types

Block access to LAN and out

docker network create -o "com.docker.network.bridge.enable_ip_masquerade"="false" lan-restricted Blocks Local LAN Internet Does not block Host running docker daemon (example access to 10.0.1.10:22)

Docker • Restricting container network access

Block access to other containers

docker network create -o "com.docker.network.bridge.enable_icc"="false" icc-restricted Blocks Containers accessing other containers on the same icc-restricted network. Does not block Access to host running docker daemon Local LAN Internet

Docker • Restricting container network access

Block access from containers to the local host running docker daemon

iptables -I INPUT -i docker0 -m addrtype --dst-type LOCAL -j DROP Blocks Access to host running docker daemon Does not block Container to container traffic Local LAN Internet Custom docker networks that doesn't use docker0

Docker • Restricting container network access

Block access from containers to the local host running docker daemon (custom network)

docker network create --subnet=192.168.0.0/24 --gateway=192.168.0.1 --ip-range=192.168.0.0/25 local-host-restricted iptables -I INPUT -s 192.168.0.0/24 -m addrtype --dst-type LOCAL -j DROP Creates a network called local-host-restricted which which: Blocks Access to host running docker daem...

Docker • Restricting container network access