Ken Thompson biography

Kenneth Lane Thompson (born February 4, 1943), commonly referred to as ken in hacker circles is an American pioneer of computer science.Kenneth Lane Thompson was the principal inventor of UNIX. Even today, more than 35 years later, UNIX and its descendants are still widely regarded as the best computer operating systems to have ever been developed.He received a Bachelor of Science in 1965 and a master's degree in 1966, both in Electrical Engineering and Computer Science, from the University of California, Berkeley, where his master's thesis advisor was Elwyn Berlekamp.Having worked at Bell Labs for most of his career.Thompson designed and implemented the original Unix operating system.In the 1960s, Thompson and Dennis Ritchie worked on the Multics operating system. While writing Multics, Thompson created the Bon programming language. The two left the Multics project when Bell Labs withdrew from it, but they used the experience from the project, and in 1969, Thompson and Ritchie became the principal creators of the Unix operating system.Thompson decided that Unix needed a system programming language and created B, a precursor to Ritchie's C language.Thompson was elected to the National Academy of Engineering in 1980 for designing UNIX, an operating system whose efficiency, breadth, power, and style have guided a generation's exploitation of minicomputers.

Lessons we learn from Ken Thompson

Thompson, like Linus Torvalds, the founder of Linux, is another example of history being shaped by the right person being ready at the right time.It is also an example of how a single person with an idea and dedication can accomplish something that eludes large organizations with huge concentrations of talent and massive budgets.He created great works not with any intention for personal profit but rather because of their dedication to their craft and their desire to improve it, with the result that the world is also improved.

What is Cyber Crimes

Cyber crime is a criminal activity committed on the internet.Cyber crime includes data diddling, logic bombing, malicious hacking.Cybercrimes committed against persons include various crimes like transmission of child-pornography, harassment of any one with the use of a computer such as e-mail. The trafficking, distribution, posting, and dissemination of obscene material including pornography and indecent exposure, constitutes one of the most important cybercrimes known today.


Forms of cyber crime:-

1. Cracking -  is amongst the gravest Cyber-crimes known till date. It is a dreadful feeling to know that a stranger has broken into your computer systems without your knowledge and consent and has tampered with precious confidential data and information.


2. Hacking - the act of gaining unauthorized access to a computer system or network and in some cases making unauthorized use of this access.


3. Piracy - the act of copying copyrighted material. The personal computer and the Internet both offer new mediums for committing an 'old' crime. Online theft is defined as any type of 'piracy' that involves the use of the Internet to market or distribute creative works protected by copyright.


4. Cyberstalking - Harassment, bullying and "stalking" persons on the Internet can occur on social networks. It frequently involves repeated and unwelcome contact with the victim by the stalker Harassment, in chatrooms or other Internet social networking sites.
 

5. Denial of service – running a program which sends thousands of requests to a site simultaneously, frequently from more than one source, so that the relevant server slows down considerably or preferably crashes.


6. Spamming - Spamming is the act of sending unsolicited messages to many users at a time, possibly up to thousands, with the usual intention of advertising products to potential customers. Spamming can also be used as a form of irritation by singling out an email address and sending the owner of that address hundreds of emails per second.

What is CRYPTOGRAPHY

Cryptography is the science or study of the techniques of secret writing, especially code and cipher systems.cryptography is now a core part of modern commerce, it is often regarded as a "black art".Today, most cryptography is digital, and the original text ("plaintext") is turned into a coded equivalent called "ciphertext" via an encryption algorithm. The ciphertext is decrypted at the receiving end and turned back into plaintext.Cryptography ensures message security over internet.

Types of Cryptography :-

1. Cryptographic checksums - Checksums help prevent undetected modification of information by encrypting the checksum in a way that makes the checksum unique.

2. Steganography - Steganography is actually the science of hiding information from people who would snoop on you. The difference between this and encryption is that the would-be snoopers may not be able to tell there's any hidden information in the first place.

3. Secret key cryptography - In secret key cryptography a single key is used for both encryption and decryption.A sender uses the key to encrypt the plain text and sends cipher key to the reciever.The reciever applies the same key

to recover the plain text.

4. Hash functions - Hash functions are also called message digests , they are algorithms without any key.A fixed length hash value is computed based upon the plain text to be recovered.Hash functions are used to provide a digital fingerprint of a file's contents to ensure that if the file has been altered by virus

What is GNU

GNU stands for Genuinely Not Unix. It is a Unix-like computer operating system developed by the GNU Project. It is composed wholly of free software. Unlike Linux, it sports the GNU Hard kernel and is intented to be a "complete Unix-compatible software system Development of GNU was initiated by Richard Stallman in 1983 and was the original focus of the Free Software Foundation.The GNU Project recommends that contributors assign the copyright for GNU packages to the Free Software Foundation  , though the Free Software Foundation considers it acceptable to release small changes to an existing project to the public domain.However, this is not required; package maintainers may retain copyright to the GNU packages they maintain, though since only the copyright holder may enforce the license used (such as the GNU GPL), the copyright holder in this case enforces it rather than the Free Software Foundation.
For the software developed under the GNU Project, Stallman wrote a license called the GNU General Public License (first called Emacs General Public License), with the goal to guarantee users freedom to share and change free software.It is also the most commonly used free software license.

Richard Stallman is operating it.

Open Source License

An open source license is a copyright license for computer software that makes the source code available for everyone to use. This allows end users to review and modify the source code for their own customization and/or troubleshooting needs. Open-source licenses are also commonly free, allowing for modification, redistribution, and commercial use without having to pay the original author. All such licenses usually have additional restrictions such as a requirement to preserve the name of the authors and a copyright statement within the code. One popular set of free open-source software licenses are those approved by the Open Source Initiative (OSI) based on their Open Source Definition (OSD).

Command line short cuts in Centos

Desktop and command line short cuts in CENTOS


[Ctrl] + [Alt] + [Backspace] = kills your current X session. Kills your graphical desktop session and returns you to the login screen. Use this if the
 normal exit procedure does not work.

[Alt] + F2 = Show the panel run application dialog 

[Ctrl] + [Alt] + [Delete] = From a non-graphical shell prompt, shuts down your Red Hat Enterprise Linux system. Use only when the normal shutdown procedure does not work. In a graphical desktop session, this shortcut displays the desktop logout screen that allows you to logout, reboot, or shut down your system.

[Ctrl] + [Alt] + [Fn] = switches screens. [Ctrl]+[Alt] + one of the function keys displays an available screen. By default, [F1] through [F6] are text-mode shell prompt screens and [F7] is the graphical desktop screen.

[Alt] + [Tab] = switches tasks in a graphical desktop environment. If you have more than one application open at a time, you can use [Alt] + [Tab] to switch among open tasks and applications. 

[Ctrl] + [a] = moves cursor to the beginning of a line. This works in most text editors and in the URL field in Mozilla.

[Ctrl] + [d] = logout of (and close) shell prompt. Use this quick shortcut instead of typing exit or logout.

[Ctrl] + [e] = moves cursor to end of a line. This works in most text editors and in the URL field in Mozilla.

[Ctrl] + [l] = clears the terminal. This shortcut does the same thing as typing clear at a command line.

[Ctrl] + [u] = clears the current line. If you are working in a terminal, use this shortcut to clear the current line from the cursor all the way to the beginning of the line. 

[Tab] = command autocomplete. Use this command when using a shell prompt. Type the first few characters of a command or filename and then press the [Tab] key. It will automatically complete the command or show all commands that match the characters you typed.

[Up] and [Down] Arrow = shows command history. When using a shell prompt, press the [up] or [down] arrow to scroll through a history of commands you have typed from the current directory. When you see the command you want to use, press [Enter]. 

[!!] = Repeat Last Command

[Alt] + [f] = Move the cursor to the end of the next word. Again, like with all shortcuts that use Alt as the modifier, this may not work in all graphical terminal emulators

[Ctrl] +[w] = Delete the word before the cursor.

[Ctrl] + [k] = Delete the line from the position of the cursor to the end of the line.

[Alt] + [b] = Move the cursor to the beginning of the current or previous word. Note that while this works in virtual terminals, it may not work in all graphical terminal emulators, because many graphical applications already use this as a menu shortcut by default.

Job scope for girls in computer science

When it comes to the computer science and technology industry, girls are an endangered species.College-aged women are realizing the opportunity that awaits them in the computer science field, even though it has been traditionally male-dominated. However, the field is growing rapidly and more minds than ever are needed to keep up with the demand.

  Demand for web designing positions tends to stay consistent, even during recessions.It has been researched in U.S that girls are more interested in the creative side, while boys are more interested in the competitive side.So the girls can use their creative mind in web development/designing viz. PHP.

 They need to do a PHP course. It includes loads of practical application-building exercises and real-life examples.

     PHP  contents:- 

1.Essential PHP elements: language structure, data types, operators, application design

2.Strings and Functions.

3.Control Statement.

4.PHP with (X)HTML

5.HTTP & HTTPS

6.Forms

7.Cookies and Sessions

8.Files management & Uploading to Server.

9.MySQL Integration.