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SEARCH KEYWORD -- Dynamic language

  The evolving history of asynchronous operation in JavaScript

JavaScript is single threaded, it means there would be only one task running at any point of time. But this would slow down the overall program execution if there is long running task, hence asynchronous task execution is desired in complex cases. To achieve asynchronous task execution, there are a few options introduced in JavaScript. setTimeout/setInterval Event Promise Async/Await setTimeout/setInterval is one of the first mechanisms introduced in JavaScript to simulate asynchronous operati...

   JAVASCRIPT,ASYNC,PROMISE,AWAIT     2019-11-09 08:21:56

  Guide on recovering data in MySQL

In our daily work, there might be mistakes made which got some data or even databases deleted in MySQL. If this happens on production, it would be a nightmare. In case this happens, normally DBA would jump in to save the world. And they would try to recover the data from the backup if there is any. But if there is no backup, then the show stops. Hence database backup is necessary on production environments to avoid such awkward situation. Also normally in MySQL, binlog should be enabled as well ...

   MYSQL,DATABASE,BACKUP,BINLOG,EXAMPLE     2020-08-26 07:50:30

  A mini post on GoLang context

In a GoLang web server, every request coming in will be handled by a goroutine. In the request handler, the logic may also need to create new goroutine to handle other tasks like RPC call. When the request is processed and response is returned, these goroutines created need to be exited so that no goroutine leak should happen. package main import ( "fmt" "log" "net/http" ) func main() { http.HandleFunc("/echo", func(w http.ResponseWriter, r *http.Request) { fmt.Println(&r) w.Write(...

   CONTEXT,GOLANG     2019-12-14 06:21:02

  SameSite attribute in cookie

Starting from Chrome 51, a new attribute SameSite has been introduced for browser cookie. This attribute is to prevent CSRF attack. Cookie is normally used to store data exchanged between client and server. It frequently stores user login information. If a malicious website can forge a HTTP request with the valid third party website cookie, it may be called a CSRF attack. For example, if a user logins to a bank website your-bank.com, the bank server responds a cookie: Set-Cookie:id=a3fWa; L...

   JAVASCRIPT,COOKIE,SAMESITE,CHROME,CSRF     2019-09-14 04:57:51

  errGroup in GoLang explained

Today, let's talk about the usage and applicable scenarios of errGroup, which is often used. Why is it useful? Generally, when we use goroutine, we cannot return a value. If you want to pass out the result of the goroutine execution, you usually have to use the channel. The errGroup package is suitable if you want to know when the goroutine you opened encounters an error during execution and stop working, and I need to know the error value. errGroup usage The package needs to be downloaded and i...

   GOLANG,ERRGROUP,WAITHROUP,CONCURRENCY     2023-05-27 23:58:20

  Fix could not read Username for 'https://xxx.com': terminal prompts disabled

Recently was working on a project which needed to build a docker image, but unfortunately it kept failing as below error was seen. fatal: could not read Username for 'https://xxx.com': terminal prompts disabled Based on the error, it looked like it was trying to pull code from remote Gitlab repository but failed as the terminal prompt is disabled. At first glance, have a doubt why it needs terminal prompt to be enabled? It should just succeed and without prompting for anything. The only reason...

   GIT,TERMINAL PROMPTS DISABLED,DOCKER     2020-12-13 04:43:12

  Use Delve to debug GoLang program

If you don't know how to debug program, you are not a real programmer. gdb can be used to debug go program, but according to golang website, delve is a better option.   Note that Delve is a better alternative to GDB when debugging Go programs built with the standard toolchain. It understands the Go runtime, data structures, and expressions better than GDB. Below is a simple go program. package main type Person struct { Name string Age int } func main() { var me Person me.Nam...

   GOLANG,DEBUG,DELVE     2018-11-09 23:28:43

  Computer skills one can learn within one day

Computer related technical skills are usually thought as complicated and difficult to understand. It's very difficult for one to get hands on one skill or master one skill. But if you really do want to learn something useful within one day, there are some good choices which will not take too long to get to know and use.. Version control:- Git, GitHub and SVN Regular expressions AWK sed Grep Learn how to do things with Vim that you never knew could be done. Set up a crawler that can scrape some ...

   Computer skills,Learn     2013-09-16 08:51:35

  How to monitor user behavior in webpage

Sometimes there is a need for website owners to monitor user behavior on the site so that they can know what pages are mostly visited and which parts are more popular so that they can provide better service to their users. These behavior usually contain user clicks, user mouse over events etc. These data can be sent back to server when triggered with some meta data. In this post, we will cover a few ways to monitor user behavior on a web portal and send data back to backend sever. 1. Synchronous...

   HTML,BEACON API,PING,USER BEHAVIOR     2019-06-29 06:06:59

  Implementing DESede/ECB/NoPadding cipher algorithm in GoLang

By default, GoLang doesn't provide the ECB mode cipher for DESede though there is CBC mode provided. In cases we need to encrypt/decrypt data with ECB mode, we need to implement those by ourselves. This mode is frequently used when encrypting/decrypting PIN block which is small block data less than 16 bytes. In this post, we will introduce how to implement the DESede/ECB/NoPadding algorithm in GoLang by using the existing cipher support. Here we will not cover how DESede works in detail, instead...

   SECURITY,SAMPLE,GOLANG,DES,DESEDE,3DES     2019-07-29 06:43:50

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