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  Use downcase! with caution in Ruby

Ruby provides ! to change state of some object in place. Hence if you see some functions have ! appended, it means the state of the caller of the function is expected to be changed. This is a very interesting Ruby feature. But sometimes one should be cautious when using this kind of functions because you would get unexpected behavior if using improperly. Let's take an example of String#downcase!. According to the documentation. Downcases the contents of str, returning nil if...

   RUBY,EXCLAMATION MARK,DOWNCASE     2017-02-10 06:34:44

  WireGuard VPN: Setup WG_VPN client App on Android phone and connect to local WG_VPN server on VM

We will show the detail steps about how to setup the WireGuard VPN client on an Android phone/pad and configure the VPN client to connect a WG_VPN server in local network. The setup process contents three main steps: Install WireGuard and create a key-pair in WireGuard client. Add the Android client peer information in the WireGuard server’s config file. Config the Android WireGuard client to connect to the server. The test environment network configuration:  Step 1. Install Wire...

   WIREGUARD,VPN,TUTORIAL     2020-10-24 08:46:42

  Microsoft: Apple UI sucks, Metro UI is philosophy

Microsoft is a typical IT company of the last century - a huge strength, but turned a little less sensitive. Now, Microsoft is trying to change the tradition of no connection between home desktop and mobile system developers, the best indicator of this effort is their design.Microsoft products, especially software products, are now gradually using a simple, plain and neat appearance: Metro. But if you think the Metro is just on Windows 8, Windows Phone, the application market and Xbox Live,...

   Windows, Metro UI,Apple     2012-04-13 07:12:21

  Using JSON in PHP

Currently JSON has become one of the most popular data exchange formats. Many website APIs support it. Since PHP 5.2, PHP provides json_encode() and json_decode() method to handle JSON encoding and decoding.1. json_encode()This function is used to transform array and objects to JSON format. First let's look one array example.        $arr = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5); 　　echo json_encode($arr);the result is{"a":1,"b"...

   JSON,PHP,json_decode(0,json_encode()     2012-05-06 06:04:42

  A simple tutorial on GoLang connecting to Clickhouse

Go, also known as Golang, is a statically-typed, concurrent programming language created by Google. ClickHouse is a high-performance, column-oriented database management system that can be used for real-time data analysis. This tutorial will provide a deep dive into how to connect to ClickHouse from a Go program, including how to perform common database operations such as SELECT and INSERT statements. Before proceeding, it is assumed that you already have Go and ClickHouse installed on your mach...

   GOLANG,CLICKHOUSE,TUTORIAL     2023-02-11 07:05:36

  How Google Utilizes Big Data for SERP

Google is an expert when it comes to big data. This is evident in their development of various techniques and open source tools which are used by the big data industry professionals. These tools and technique allow Google to sift through millions of different websites and enormous amounts of data in order to provide users with correct answers in a matter of milliseconds. But how does Google accomplish that with such precision? To answer that, we need to focus on the complex activities that go o...

   GOOGLE,BIG DATA     2017-05-31 16:13:03

  Mobile devices are facing new threats

More and more companies allow employees to use smartphones and tablet PCs in workplace, but they are facing a new potential threat - malware embedded in games and applications.Dan Hoffman, network security company Juniper Networks mobile security director, said the application store is quickly becoming the main delivery mechanism of infected applications. Consumers purchase applications for their equipments through an online application store.As the consumers are free to download applicatio...

   Mobile device,Data security,Malicious software     2012-04-05 13:00:57

  The confusing strtotime() function in PHP

Frequently PHP programmers get confused of the use of i month, -1 month, next month in strtotime() function. and hence it leaves some impression to programmer that this function is not that reliable. Let's take one example of strtotime call with -1 month and see why it leaves this impression. date("Y-m-d",strtotime("-1 month"))  // Assume today is 2018-07-31 What's the output of above call? The answer is 2018-07-01. Why not 2018-06-30? So people get confused. It appears that this is ...

   PHP,STRTOTIME,FIRST DAY OF,-1 MONTH     2018-08-04 05:49:32

  NIO vs IO in Java

Java 1.4 provides a new API for handling IO -- NIO. This is a non-blocking and buffer oriented IO API. Below are main differences between the NIO and IO in Java. IO NIO Stream oriented Buffer oriented Blocking IO Non-blocking IO N/A Using selector Stream oriented vs Buffer oriented The main difference is that IO is stream oriented where the data is read byte by byte and the data will not be buffered normally.This means there is no pointer to move forward and backward in the stream. I...

   JAVA,IO,NIO     2016-01-10 01:40:02

  Different types of keystore in Java -- PKCS12

PKCS12 is an active file format for storing cryptography objects as a single file. It can be used to store secret key, private key and certificate.It is a standardized format published by RSA Laboratories which means it can be used not only in Java but also in other libraries in C, C++ or C# etc. This file format is frequently used to import and export entries from or to other keystore types. Next we will explain the operations which can be performed on PKCS12 keystore. Create PKCS12 keystore Be...

   Java, PKCS12, keystore, tutorial     2015-01-04 21:08:49

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