SEARCH KEYWORD -- Data security

  The roots of Lisp

(I wrote this article to help myself understand exactly what McCarthy discovered. You don't need to know this stuff to program in Lisp, but it should be helpful to anyone who wants to understand the essence of Lisp-- both in the sense of its origins and its semantic core. The fact that it has such a core is one of Lisp's distinguishing features, and the reason why, unlike other languages, Lisp has dialects.)In 1960, John McCarthy published a remarkable paper in which he did for programming somet...

   Lips,Root,McCarthy,AI,Artificial Intelligence     2011-10-25 10:35:13

  Set file permission in Java

Prior to Java 6,  there is no good solution at the Java level to provide file permission management. You need to implement your own native methods or call the Runtime.exec() to invoke the system routine such as chmod in LInux. Since Java 6, Java introduces a set of methods which can be used to set the file permission at Java level. These methods include: File.setReadable(boolean); File.setWritable(boolean); FIle.setExecutable(boolean); File.setReadable(boolean, boolean); File.setWritable(bo...

   JAVA, FILE PERMISSION, POSIX,learnjava     2015-08-29 03:37:37

  The war with spam comment

Spam comments are annoying and notorious. They are either malicious data from hackers to exploit the loopholes of the site or advertisements posted by robots. These kinds of comments have their own features and patterns, if we are careful enough, we can find ways to block most of them although it's not so easy. To block the comment with malicious executable codes such as JavaScript, we should remember one rule : never trust user input. So wherever there are user inputs, we need to check the vali...

   Spam comment,Block,Filter     2013-11-29 20:29:43

  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

  Fujitsu CTO: Flash is just a stopgap

Flash is a necessary waystation as we travel to a single in-memory storage architecture. That's the view from a Fujitsu chief technology officer's office. Dr Joseph Reger, CTO at Fujitsu Technology Solutions, is that office-holder, and – according to him – flash is beset with problems that will become unsolvable. He says we are seeing increases in flash density at the expense of our ability to read and write data. Each shrink in process geometry, from 3X to 2X and onto 1X, ...

   Flash,Memory,Bottleneck,Limitation,Futur     2011-08-12 07:31:34

  The danger of target=_blank and opener

When want to open a new page in a new tab on clicking a link on a page, the usual way of achieving this is to use target="_blank" property in a tag. However, the use of this leaves space for phishing website. Background parent and opener Before talking about the opener object, let's know a bit about parent object when using iframe. HTML provides a parent object which is used to communicate between the parent page and the embedded iframe element. This parent object can be accessed using...

   HTML,TARGET BLANK,REL NOOPENER,REL NOREFERRER     2018-09-15 04:53:56

  Launch Java process programmatically in Java

In some cases while working on some automation testcase, developers would like to launch Java process programmatically so that the tests can be ran without manual intervention. Java provides such methods to achieve this. ProcessBuilder can be used to build a Java process which can be launched when everything is ready. Basically it can take a list of parameters which are similar to the command line options/arguments.  For example, if you want to launch a Java process, you can do followi...

   JAVA,PROCESSBUILDER,COMMAND LINE     2016-04-27 04:03:30

  SkipList in Go

Algorithmic thinking is the must-have in the coding world, so I have been keeping the routine of algorithm practice every week, consolidating my knowledge of data structures on one hand, and improving my coding skills as well. A difficult one happened to be stuck in my mind- Implement SkipList with Go, which took me quite a weekend. Below is the front-line report of how I finally got the hang of it. First, from its concept. Wiki has explained it well. a skip list is a probab...

   GOLANG,SKIPLIST     2022-04-05 02:21:59

  Python and PLC Communication

This article provides detailed steps on how to use Python to communicate with Schneider M221 and Siemens S7-1200 PLCs via Ethernet. Additionally, we offer a packaged Python PLC client library, enabling you to easily build your own SCADA control programs, such as Human-Machine Interfaces (HMI). The system overview is shown below: To check the project detail please refer to Python Physical PLC Communication Clients # Created: 2024/06/29 # Version: v0.1.3 # Copyright: Copyright (c) 2024 ...

       2024-06-30 02:21:17

  The Go Pointer Magic

Go is a language with the pointer type, by which we can Pass pointer into a function and update value in-place. Add methods to a struct as (* T) A, which is different from (T) A(). However, the pointer is type-safe in Go, meaning that there are such restrictions of the pointer. Different types of pointers are unconvertible. Pointer type cannot be used for calculation. Pointer types cannot be compared, either == nor !=. No mutual assignment between different pointer-...

   GOLANG,POINTER,UNSAFE     2021-10-03 02:18:57

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