Yet Another Blog

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Network on virtual machine

July 7, 2022

xxx is not in the sudoers list

TL;DR: Add desired user to the sudoers group. 1 2 3 4 # switch to root su - root # add your name to group wheel, which is exactly sudoers group usermod -aG wheel [USERNAME]

July 5, 2022

Install MySQL 5.7 on CentOS7

TL;DR: download rpm, import GPG key and yum install. MySQL 5.7 improves security and performance over previous versions, also introduces the JSON data type, allowing to store non relational da...

July 5, 2022

Could not resolve host on CentOS7

TL;DR: config network card file I met this problem when I installed minimal version of CentOS 7.9 on virtualbox. It results from the default minimal setting which turns off the network card se...

July 5, 2022

九故事

Comment: Nine Stories is a collection of short stories by American fiction writer J. D. Salinger. I was deeply moved by those vivid characters in these stories, among which is most impressed by For...

June 30, 2022

Job hunting tips, Business English Learned from Lucy

How to write a perfect CV A CV does not get you a job, what a CV actually gets you is a job interview. There is absolutely no excuse for a mistake on a CV. The relevant skills and experience, wit...

June 26, 2022

茶花女

Comment: Marguerite, are you lonesome tonight? 一个月里有二十五天玛格丽特带的茶花是白的，而另外五天她带的茶花却是红的，谁也摸不透茶花颜色变化的原因是什么，而我也无法解释其中的道理。在她常去的那几个剧院里，那些老观众和她的朋友们都像我一样注意到了这一现象。除了茶花以外，从来没有人看见过她还带过别的花。因此，在她常去买花的巴尔戎夫人的花店里，有人...

June 25, 2022

从面向对象出发总结Java重难点知识

TL;DR: 从面向对象出发，再回到面向对象。 Java是一门纯粹的面向对象语言，所有对象继承自java.lang.Object。直白一点说，我们即使实现一个简单的功能、写一道算法题，也要先定义一个类（class），然后再在类里面实现。因此，在我看来，所有Java的语言特性及其背后的基本原理、设计理念都可以追溯到面向对象当中。我们不妨先问自己一个常见的面试题：谈谈你对面向对象的看法？ ...

June 23, 2022

Binary Representation of Numbers in Computer Science

How infinite numbers are represented under limitation of finite bits? In this blog, we focus on representations of integers and floating point numbers. Integers Above is the philosophy of the bina...

June 22, 2022

Philosophy of binary representation: finite bits VS infinite information

TL;DR: Bits are not everything. Everything can be bits. It is widely know that data are encoded as 0-1 representation in comupter science due to its electronic implementation. But what is the behin...

June 20, 2022