SEARCH KEYWORD -- type system


  How DNS lookup works

When accessing a website, a domain name would be needed normally. To get to the actual web server, the domain name must be mapped to an actual IP address and the IP address will be used to reach the web server. The process of finding the IP address from a domain name is called DNS lookup.  How does DNS lookup work? There are tons of domain name and IP address around the world, there must be some well-designed architecture to support fast lookup. This post will explain how this works. DNS Se...

   DNS,DNS LOOKUP     2022-09-09 23:11:03

  PHP to get long running process progress dynamically

Frequently in web applications, we may have a request to the back end system which may trigger a long running process such as searching huge amount of data or a long running database process. Then the front end webpage may hang and wait for the process to be finished. During this process, if we can provide the user some information about the progress of the back end process, it may improve user experience. Unfortunately, in web applications, this seems not an easy task because web scripting lang...

   AJAX,PHP,progress,long process,demo     2012-06-04 07:29:37

  Empty slice vs nil slice in GoLang

In Go, there is a type called slice which is built on top of array. It's a very convenient type when we want to handle a group of data. This post will explain a subtle but tricky difference between empty slice and nil slice. A nil slice is a slice has a length and capacity of zero and has no underlying array. The zero value of slice is nil. If a slice is declared like below, it is a nil slice. package main import "fmt" func main() { var a []string fmt.Println(a == nil) } The output will be t...

   GOLANG,JSON,EMPTY SLICE,NIL SLICE     2018-10-18 09:25:21

  Common usage of ls command in Linux

In Linux, ls might be one of the most frequently used commands. It is used to list files in a specific directory. In most cases, we may just use ls -l to list the files under a directory. But have you explored other usages of this command. In this post, we will summarise some other common usages of ls command Assuming we have below directory structure in our system, let's see them using tree command. List details of the files If we want to list the details of the files in /home/alvin/test_...

   LINUX,SHELL,LS     2018-12-16 03:00:42

  Cool things you can do with iPhone

Nowadays smart phones have plenty of cool features you can get to know without reading the manuals. But do you know there are some useful but less well known features which can ease our life? In this post, we will share with you some cool features on iPhone. If you have an iPhone with, go and get a try. 1. Use Google Map as free GPS While traveling abroad, you can use Google Maps as a free GPS without an international data plan by making use of it's hidden offline maps feature.You can use this f...

   iPhone,Feature     2013-10-05 07:28:07

  A simple tutorial on writing Java native program

Java provides Java Native Interface(JNI) to enable developers to write programs which can utilize the underlying native libraries of the operating system. The benefits of writing native code are that they normally provide better performance compared to Java codes. Sometimes if you want to utilize some system specific functions you may also want to use JNI. One main drawback of writing native code is that your application may not be platform independent anymore. This is not what Java is desi...

   Java native interface, JNI, Native code, Sample     2015-08-15 08:28:15

  Turn browser into notepad with one line of code

This is the code shared by Jose on codewall. When you type data:text/html,   into the address bar of the browser and press enter, the browser will turn into a notepad which you can edit. Why it works? This uses Data URI’s format and it tells the browser to render HTML. But contenteditable is a property of HTML5, so this can only work in the web browser which supports this property. Here are some interesting contents. Some people make some changes to the code encouraged by the ide...

   HTML5, Browser editor     2013-01-30 04:20:54

  One reason why mcrypt responds slowly

This morning one colleague came over and talked about one script which used mcrypt responded very slowly, the server configurations are fine. But the reason for the slowness is unknown. Here is one script which reproduces the issue: <?php $dmcryptText = "dummy"; $key = "foobar"; $size = mcrypt_get_iv_size(MCRYPT_BLOWFISH,MCRYPT_MODE_ECB); $iv = mcrypt_create_iv($size); //Take care $m = mcrypt_ecb(MCRYPT_BLOWFISH, $key, $dmcryptText, MCRYPT_DECRYPT, $iv); var_dump($m); When 20 requests of&...

   SOLUTION,SLOW,MCRYPT,RESPONSE,PHP     2012-09-27 12:03:16

  Microsoft's next generation OS Windows Blue may be free

In PC era, Microsoft is the world's largest software service provider, its revenue  is mainly from selling operating systems and other software services.With the advent of the era of mobile Internet, the free software service concept has been widely accepted, Microsoft has been forced to explore new business models.According to ZDNet, Microsoft's next-generation OS Windows Blue is expected to be released in mid of 2013. The biggest difference between the new version of the OS and the previ...

   Windows Blue, Pirce, Free     2012-11-29 10:54:15

  What is Deep Web- all you need to know about it?

Deep web is the most nefarious out of sight underground area that exists and not accessible to the public domain. The deep web sites cannot be accessed through standard search engines. Many experts believe to have compared this part of the internet hidden from paywalls and forms. The truth is that deep web is a hidden iceberg while the usual internet available to the public domain is just the tip of the iceberg. That part of what is available from search engines such as Bing or Google ...

   DEEP WEB,DARK WEB     2018-07-05 08:26:58

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