• Linux permission management (1) basic permissions


    1、 File types and permissions -rwxrw-r– The first character indicates the file type If-, indicating a normal file Ifd, indicating directory Ifl, indicating a linked file IfbIndicates the interface device available for storage in the device file IfcIndicates the serial port device in the device file, such as mouse and keyboard The second to fourth […]

  • Analysis of poll epoll implementation (II) — epoll implementation


    Relevant video recommendations During the interview, I was serious about the “eight part essay” network principle TCP / UDP and network programming epoll / reactorAnalysis of epoll principle and application of reactor modelAnalysis of epoll principle and treatment of three grip and four swingLinux c + + background server development architect free learning address Through […]

  • Go: Map Design (1)


    [translation]Original addressThis article is the first in a series of three articles, each of which will cover a part of go map. It is recommended that you read it in order.Map type is a built-in type of go language, which is implemented by the principle of hash table. In this article, we will explore the […]

  • Web ml + webassembly supports the background blur function of Google meet


    Text/Tingbo Hou & Tyler Mullen, software engineer, Google Research Institute Translator/Alpha Technical reviser: Betta front-end expert, Wang Xingwei Original text/https://ai.googleblog.com/202… Video conference is becoming more and more important in people’s work and life. We can improve the video experience by enhancing privacy protection or adding interesting visual effects, while helping people focus on the content […]

  • Lane change detection of vehicle


    Author | hitesh valechaCompile VKSource: towards Data Science In this tutorial, we will learn how to use computer vision and image processing to detect whether a car changes lanes on the road. You must have heard that opencv Haar cascade can detect faces, eyes, cars, buses and other objects? This time, let’s use this simple […]

  • Leetcode practice – bit operation (division of two numbers, numbers that appear only once, repeated DNA sequences, etc.)


    preface The operation of 0 and 1 is the bottom operation of the computer. All programs, no matter what language they are written in, must be transformed into a language that the machine can understand, that is, binary for basic operations, and these basic operations are the bit operations we want to talk about today. […]

  • “Yunguang” international exhibition, CES 2021 wonderful products selection!


    CES is a large-scale consumer electronics exhibition held in Las Vegas in January every year. This year, due to the special reasons of the epidemic, this large-scale exhibition, which has been held for more than 50 years, has been switched to online for the first time. According to the American consumer Technology Association, about 4000 […]

  • Initial websocket


    I’ve always been interested in real-time communication. I took the time to learn about websocket this week. websocket Websocket is a network transmission protocol, which can carry out full duplex communication on a single TCP connection. It is located in the application layer of OSI model. Websocket makes the data exchange between the client and […]

  • Websocket from entry to mastery, half an hour is enough!


    The original title of this article is “websocket: 5 minutes from getting started to mastering”, and the author is “program ape small card”_ Casper “, see the resources section at the end of the text for a link to the original text. There are changes in this collection. 1. Introduction Since the emergence of websocket […]

  • JS file transfer, 10 HTML file upload skills, web user experience design improvement guide, strange knowledge — bitmask | si no technology weekly


    Today, I share the knowledge points to improve work happiness. I hope you don’t miss these good articles~ 1、JS files Base64, file, blob and arraybuffer are transferred to each other Binary conversion File object to Base64 let reader = new FileReader();  reader.readAsDataURL(file[0])  console.log(reader) Convert Base64 to blob upload function dataURItoBlob(dataURI) {       var byteString = atob(dataURI.split(‘,’)[1]);       var mimeString = dataURI.split(‘,’)[0].split(‘:’)[1].split(‘;’)[0];       var ab = new ArrayBuffer(byteString.length);       var ia = new Uint8Array(ab);       for (var i = 0; i < byteString.length; i++) {           ia[i] = byteString.charCodeAt(i);       }       return new Blob([ab], {type: mimeString});   } Convert […]

  • Locking pages while waiting for long operation based on angular


    Due to the network and other reasons, sometimes it takes a long time to execute an Ajax operation. If you don’t do special processing, you can’t know the status of the current operation, which seriously affects the user experience. A common solution is to open a mask before performing a possible long operation, cover the […]

  • Qianxin school move: buy masks (c + +)


    ⭐ Article link: www.mengyingjie.com/archives/38/ ⭐ Time limit: 1 second for C / C + + and 2 seconds for other languagesSpace limit: C / C + + 26214k, other languages 524288K64bit IO Format: %lld Title Description Xiaoming has n yuan to go to the drugstore to buy masks. There are 6 brands of masks in […]