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  JavaScript cross domain request solution

1. What is cross domain? We may often using AJAX to request data from other domain, now we will have cross domain request issues. It's because JavaScript only allows to request data from the same domain because of security consideration. In short, same domain strategy means a piece of code can read data from the same source, the same source here means the combination of the same domain, protocol and port number. For example: URLDescriptionAllow communication? http://www.a.com/a.js http:/...

   AJAX,cross domain,security     2013-03-13 20:04:52

  Significance and use of do{...}while(0)

In some Linux kernel and other open source codes, we can see some codes like below: do{ ... }while(0) This code snippet is not a loop, it seems there is no significance of using do...while this way, then why should we use it? In fact, the significance of do{...}while(0) is better than optimizing your code. After some research, we summarize some benefits of it. 1. Help define complex macro to avoid error #define DOSOMETHING()\ foo1();\ foo2(); The me...

   do{...}while(0), optimization     2012-10-21 21:13:22

  How to find which process a file is being written by in Linux?

Some people ask a file is being written by one process and they want to check this process, but they cannot find the process even with sof. This question is very common and there are many solutions, here we introduce a straightforward method. In Linux, each file will be stored on one device and of course there will be a relative inode, then we can use vfs.write to know who is writing the inode on one specified device continuously. Luckily there is inodewatch.stp in the installation package of s...

   Linux,process,file write     2013-03-16 21:44:35

  Power Grid OT Simulation System

Mini OT-Energy-System Cyber Security Digital Twin Figure-00: Power_Grid_OT_Simulation_System Environment Diagram, version v0.1.2 (2024) Project Design Purpose: The primary objective of this project is to develop a scaled-down Operational Technology (OT) digital twin/equivalent — an advanced software simulation system capable of emulating the functionality of an small-sized 18KW (560+MkWh/year) hybrid power grid. This system will meet the requirements for cybersecurity training, exercises...

       2024-10-13 09:00:12

  10 design flaws of JavaScript

JavaScript's design took only ten days. Moreover, the designer didn't want to design it initially, he just wanted to complete the task assigned by company. It is now a very powerful client side programming language used in almost all the websites. It's an excellent language, but it also has some flaws. 1. Not suitable for large projects JavaScript doesn't have namespace, it's hard to be modular, there is no standard for putting codes in multiple source files. It allows defining functions with th...

   JavaScript, Design flaw, Object     2012-11-29 11:39:35

  PHP 7 is coming soon

After a few RCs, PHP 7 will be officially released on November 12, 2015. This is a major release of PHP since PHP 5.6. @Laruence, one of the core contributors of PHP, has posted this news on Weibo(China's Twitter).  This is a one month later than the expected time as recorded in PHP 7 timeline. But it's not that late. The new release will come with a few features including: Scalar type declaration, you can define variable like int now Return type support. Besides declare scalar type ...

   RELEASE DATE,PHP7     2015-11-08 09:13:37

  Mobile payment status quo in Singapore

Currently there are lots of mobile payment companies operating in Singapore, these players include GrabPay(a subsidiary of Grab), AliPay, WeChat Pay, Fave Pay, NETS Pay and some others. In some hawker centers, you can see QR code from different companies. This brings lots of benefits to users. But this introduces a big headache to consumers as they have to download different apps to use in different merchants. There is no dominating mobile payment company in Singapore though there are a few lead...

   SINGAPORE,GRAB,GRABPAY,ALIPAY     2019-02-27 07:19:49

  What have been Facebook’s greatest technical accomplishments?

To maintain a large website which gets billions of requests er day and keeps very fast response speed is not an easy task. Many big companies are trying best to improve user experience by adopting different techniques. There is a question on Quora which asks "What have been Facebook’s greatest technical accomplishments?". There is a person who worked in Facebook before provided an answer which helps us understanding how Facebook handles huge amount of traffic each day. Here is the answer f...

   Facebook, Design, Efficiency     2013-01-15 07:32:07

  Server monitoring shell scripts

There are many open source server monitoring software such as cacti and nagios. Besides these, can we write our own shell scripts to monitor them? The shell scripts written by ourselves can fulfill our special requirements better and have a more detailed coverage. Below are some commonly used shell scripts used by Evangelist, an Oracle DBA. 1. Check network gateway traffic #!/bin/bash #network #Mike.Xu while : ; do time='date +%m"-"%d" "%k":"%M' day='date +%m"-"%d' rx_before='...

   Server monitor,CPU,memory,shell     2013-08-30 21:56:14

  Is Singapore a good place for startups?

Singapore is long time being considered as a perfect place for living and investing given its beautiful environment, warmly climate,  well-polished legal system and well-known richness. Its government is relatively young and open-minded. They like to take new challenges and embrace new technologies. It's the first country to open its government data to the world online. Many of you may consider that Singapore would be a perfect place for you to start your next startup. But the tr...

   SINGAPORE,STARTUP     2016-03-09 09:06:32

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