The most concise Linux commands

1. ls command View the visible files, folders and their related permissions in the current directory Common parameters: - l list view -al view all, including hidden files and folders [root@qinshengfei bin]# ls --color in color [root@qinshengfei bin]# ls -l detail list catalog file [root@qinshengfei bin]# ls -a shows all files, inc ...

Posted on Thu, 20 Feb 2020 04:37:18 -0500 by tomm098

Python version of classic thermostat strategy

abstract The trend market will not last forever. In fact, the market is in a volatile market most of the time, so some people hope to get a trading strategy, which can be used in both the trend market and the volatile market. So today, we will use the inventor's quantitative trading platform to build a classic thermostat strategy for general t ...

Posted on Thu, 20 Feb 2020 03:25:01 -0500 by bonzie

Go into HashMap -- implementation principle and source code analysis

HashMap is a very important container in JDK. It is implemented by array + linked list. Ideally, it can support the operation of adding, deleting, modifying and querying O(1) time complexity. This article will explain the implementation principle of hash table from simple to deep, and analyze part of the source code of HashMap. 1. F ...

Posted on Thu, 20 Feb 2020 02:57:27 -0500 by catalin.1975

python log processing exercise

1 overview of log collection 1 log collection process In the production process, there will be a large number of system logs, application logs, security logs and other logs. Through the analysis of logs, we can understand the load and health of the server, analyze the distribution of customers, the behavior of customers, and even make predict ...

Posted on Wed, 19 Feb 2020 23:48:43 -0500 by timbo6585

Learn java from scratch (18)

Day8 Continue to learn about classes and methods today 1. Storage and transfer of values of different data types Data type: Basic data types: only 8 Reference data type: except basic data type Difference: Different storage methods: basic data types store values, and reference data types store address ...

Posted on Wed, 19 Feb 2020 11:29:07 -0500 by simcoweb

CrackMe160 learning notes 049

Preface Although this topic is simple, it gives people a sense of immediate brightness. On the Mac terminal, 0 and O are similar. I made a mistake at the beginning and didn't find out. thinking First find the location of the judgment. Step by step analysis. You can see that there are 7 failed jumps ...

Posted on Wed, 19 Feb 2020 11:07:49 -0500 by deeem

Redis design and implementation note Chapter 11 AOF persistence

AOF persistence APPEND ONLY FILE AOF persistence Compared with RDB persistence, when RDB initiates initialization, all objects in the current database will be persisted once. Even if there is such a saving method as BGSAVE command, certain resources will be occupied when saving. And most of the data m ...

Posted on Wed, 19 Feb 2020 08:15:08 -0500 by runsum

[Java learning] basic syntax

I. annotations Single-Line Comments //Note content multiline comment /* Note Content */ Text Annotation /** Note Content */ 2, Identifier Key word abstract assert boolean break byte case catch char class const continue default do double else enum extents final finally float for g ...

Posted on Wed, 19 Feb 2020 07:09:50 -0500 by sidhumaharaj

Unity - micro phone test recording, play recording, display sound wave chart (not Spectrum chart)

I've been looking for inspiration for game design recently. Looking for it, I suddenly remembered that in a previous airplane game, end game, he could automatically fire bullets according to the music files you played. The players could not fire bullets on their own. At that time, I always took a piece ...

Posted on Wed, 19 Feb 2020 06:22:22 -0500 by squariegoes

Python 3 standard library: enum enumeration

1. enum Enumeration is a collection of symbol names (enumeration members). Enumeration members should be unique and immutable. In enumeration, members can be compared in identity, and enumeration itself is iterative. 1.1 create enumeration You can use class syntax to derive Enum and add class properties that describe values to define a new enum ...

Posted on Wed, 19 Feb 2020 05:24:05 -0500 by TexasMd91