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Basic Knowledge of XML – Creating an XML Document

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After you read my article few days ago, XML - Introduction to XML Programming, now you have an understanding of what XML is and how it works, it’s time to learn how to apply your knowledge and design your own set of XML markup tags, and then use those tags to write your first XML document. In this article, you’ll learn step-by-step how to do this, along with other design features, to build a working XML document that enables you to share information electronically among various applications.
This section follows an old programmer’s tradition of introducing a new language with a program that prints “Hello World” on the console. XML is a markup language, not a programming language; but the basic principle still applies. Let’s do that.

Creating a Simple XML Document

In this section, you’ll create a simple XML document and save it in a file. Code below is about the simplest XML document I can imagine, so start with it. You can type this document in any convenient text editor, such as Notepad, G-Edit, or Emacs.

Hello.xml

<?xml version=”1.0”?>
<root>
Hello XML!
</root>

That code is very simple, but it is a good XML document. To be more precise, it is a well-formed XML document. XML has special terms for documents that it considers “good” depending on exactly which set of rules they satisfy. “Well formed” is one of those terms, but we’ll get to that later.

Loading the XML File into a Web Browser

Now that you’ve created your first XML document, you’re going to want to look at it. You can open the file directly in a browser that supports XML such as Internet Explorer 5.0 or later. Figure at below shows the result; display Hello.xml in Internet Explorer 6.0.

XML in Browser

Congratulation you finally done your first XML document. Now you’re ready to continue for more advance topic of XML. Ha ha, it’s very little knowledge about XML, but it’s very useful to you, especially the root tag, so don’t be underestimate with those tag, I’ve tell you. See you in next article about XML, DTD – Document Type Definitions.

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The New Language from Microsoft - F#, a Functional Programming Language

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F# (pronounced F sharp) is a functional and object oriented programming language for the Microsoft .NET platform. F# is a variant of the ML programming language. F# can be used to access hundreds of .NET libraries, and the F# code can be accessed from C# and other .NET languages. Functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast with the imperative programming style that emphasizes changes in state.

See the latest release and download information for the Microsoft Research implementation of F# at here. The following steps guide you to download, install, and compiling your first program, with F# version 1.1.12.6 with .NET 2.0, and then let’s try the “Hello World” program below:

• From Add/Remove programs, uninstall any previous F# installs.
• Download F# and save the zip file locally.
• Extract the files to a temporary location.
• Run the .msi installer from that directory. This requires .NET 2.0.
Note, if you have Visual Studio, the installer will run devenv /setup which takes some moments.
• Add the F# bin directory to your path:
set PATH=c:\Program Files\FSharp-1.1.12.6\bin\;%PATH%
• fsc is the command line compiler. You can list the command line options as follows:
fsc -help
• Create a source directory.
• Create a .fs file, containing:
printf "Hello World!\n"
• Compile it to give a hello.exe which you can run.
fsc hello.fs hello.exe

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XML Programming - Introduction to XML Programming

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What is XML?

The following points can explain the purpose of XML.

  • XML stands for eXtensible Markup Language
  • XML is a markup language much like HTML.
  • XML was designed to describe data.
  • XML tags are not predefined in XML. You must define your own tags.
  • XML uses a DTD (Document Type Definition) to describe the data.
  • XML with a DTD is designed to be self describing.

It is important to understand that XML is not a replacement for HTML. The main purpose of HTML is the Format the Data that is presented through Browser. The purpose of XML is not to Format the Data to be displayed. It's mostly used to store and transfer data and to describe the data. It is device or language independent and can be used for Transmitting Data to any device. The Parser (Or the Program which is capable of understanding the Tags and returning the Text in a Valid Format) on the corresponding device will help in displaying the data in required format.

You can define your own tags in XML file. The way these tags will be interpreted will depend on the program which is going to get this XML file. The data embedded within these tags will be used according to logic implemented in the secondary program which is going to get this XML as feed. This point will be clearer when we start explaining you about how to use the Parsers in next few paragraphs.

XML Declarations

Most of the XML tags have a name associated with it. Here we explain different terms used to indicate the Elements defined in the XML file.

Well Formed Tags:

One of the most important features of a XML file is it should be a Well Formed File. What it means is all the tags should have a closing tag. In a HTML file, for some tags like <br> we don't have to specify a closing tag called </br>. Where as in a XML file, it is compulsory to have a closing tag. So we have to declare <br></br> or <br/>. This are what called as Well Formed Tags.

Elements and Attributes:

Each tag in a XML file can have elements and attributes. Here's how a typical tag looks like.

<Email
to="admin@mydomain.com"
from="user@mySite.com"
subject="Introducing XML">
</Email>

In this example, Email is called as Element. This element called Email has three attributes, to, from and subject.

The Following Rules need to be followed while declaring the XML Elements Names:

  • Names can contain letters, numbers, and other characters
  • Names must not start with a number or "_" (underscore)
  • Names must not start with the letters xml (or XML or Xml ..)
  • Names can not contain spaces

Any name can be used, no words are reserved, but the idea is to make names descriptive. Names with an underscore separator are nice.

Examples: <author_name>, <published_date>.

Avoid "-" and "." in names. It could be a mess if your software tried to subtract name from first (author-name) or think that "name" is a property of the object "author" (author.name).

Element names can be as long as you like, but don't exaggerate. Names should be short and simple, like this: <author_name> not like this <name_of_the_author> .

XML documents often have a parallel database, where fieldnames parallel with element names. A good rule is to use the naming rules of your databases.

Non-English letters like éòá are perfectly legal in XML element names, but watch out for problems if your software vendor doesn't support it.

The ":" should not be used in element names because it is reserved to be used for something called namespaces.

Empty Tags:

In cases where you don't have to provide any sub tags, you can close the tag, by providing a "/" to the Closing Tag. For example declaring

<Text></Text> is same a declaring <Text/>

Comments in XML File:

Comments in XML file are declared the same way as Comments in HTML File.

<Text>Welcome To XML Tutorial</Text>
<!-- This is a comment -->
<Subject/>

The XML Prolog

XML file always starts with a prolog. The minimal prolog contains a declaration that identifies the document as an XML document, like this:

<?xml version="1.0"?>

The declaration may also contain additional information, like this:

<?xml version="1.0" encoding="ISO-8859-1" standalone="yes"?>
  
The XML declaration may contain the following attributes:
  
version 
  
Identifies the version of the XML markup language used in the data. This attribute is not optional. 
    
encoding 
  
Identifies the character set used to encode the data. "ISO-8859-1" is "Latin-1" the Western European and English language character set. (The default is compressed Unicode: UTF-8.).
    
standalone 
  
Tells whether or not this document references an external entity or an external data type specification (see below). If there are no external references, then "yes" is appropriate.

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Philosophy of Ubuntu Linux





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Work is driven by a philosophy on software freedom that aims to spread and bring the benefits of software to all parts of the world. At the core of the Ubuntu Philosophy are these core philosophical ideals: 
  
  1. Every computer user should      have the freedom to download, run, copy, distribute, study, share, change      and improve their software for any purpose, without paying licensing fees.      
  2. Every computer user should be      able to use their software in the language of their choice.
  3. Every computer user should be      given every opportunity to use software, even if they work under a      disability. 
  
This philosophy is reflected in the software and included in distribution. As a result, the licensing terms of the software are measured against this philosophy, using the Ubuntu License Policy. 
  
When you install Ubuntu almost all of the software installed already meets these ideals, and the developer working to ensure that every single piece of software you need is available under a license that gives you those freedoms. 
  
  
Free software
  
For Ubuntu, the 'free' in 'free software' is used primarily in reference to freedom, and not to price. The most important thing about Ubuntu is that it confers rights of software freedom on the people who install and use it. It is these freedoms that enable the Ubuntu community to grow, continue to share its collective experience and expertise to improve Ubuntu and make it suitable for use in new countries and new industries. 
  
Quoting the Free Software Foundation's 'What is Free Software', the freedoms at the core of free software are defined as: 
  
  • The freedom to run the      programme, for any purpose.
  • The freedom to study how the      programme works and adapt it to your needs. 
  • The freedom to redistribute      copies so you can help others. 
  • The freedom to improve the      programme and release your improvements to the public, so that everyone      benefits. 
  
Open source

Open source is a term coined in 1998 to remove the ambiguity in the English word 'free'. The Open Source Initiative described open source software in the Open Source Definition. Open source continues to enjoy growing success and wide recognition. 
  
Ubuntu is happy to call itself open source. While some refer to free and open source as competing movements with different ends, never see free and open source software as either distinct or incompatible. Ubuntu proudly includes members who identify with both the free software and open source camps, and many who identify with both.
  
Info : Ubuntu 7.10 code name Gutsy Gibbon released, October 15, 2007, and already be available for free download on Thursday 18 October.
  
Source : http://www.ubuntu.com
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0-Day - the Doomsday





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The DoomsdayYou must be heard a unstoppable killing machine named Doomsday that was successful overcame Superman in the DC's comic. The day at the time of Doomsday defeat Superman was the doomsday, the destruction day of humankind. Like doomsday, 0-Day (Zero-Day) is a doomsday for software developer.


0-Zero Day is a term that was difficult to be proven the existence. Meaning that, the person often named this term, but in practice it was said almost had not been found. Zero-Day that I intention here often was mentioned by Zero-Day (hour) attack/exploit.

In my opinion, not was unknown, but was difficult to be proven that was a zero day attack. The term derives from the age of the exploit. A Zero-Day exploit is almost always unknown to the public and to the software developer, but generally circulate through hackers until finally being released on public forums.

In the other word, A Zero-Day attack is one that takes advantage of a security vulnerabilitZero Day Attacky on the same day that the vulnerability becomes generally known. After someone detects there is a software contains a potential exposure to exploitation. That person can notify the software developer and sometimes the world at large so that action can be taken to repair the exposure or defend against its exploitation. Unfortunately, sometimes had someone who was successful make use of this vulnerability before software developer succeeded in fixing that software.

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