Some Interesting Facts About GNU/Linux

Some Interesting Facts About GNU/Linux :

    Linux is a land of excavation, the more you excavate the more you find treasure lies within it. This article tries to uncover some of the lesser known facts about Linux. To keep things simple, easy to read, easy to remember and easy to refer this article will be presented in point-wise fashion.

  

# Linux is not an OS, but it is the kernel, GNU Linux is the OS and it comes in several hundred flavours.

# Linux Kernel was written by a 21 year finnish college student as a part of his hobby. Yup! His name is Linus Torvalds.

# Torvalds created Linux based on GNU General Public License (GPL). Perhaps Torvalds would have never written his own kernel if GPL would be having it’s own kernel and driver.

# Major part of today’s Linux kernel is written in C programming language and assembly language and only 2% of today’s kernel contains code written by Torvalds.

# A Standard Linux Kernel of today has over 10 Million lines of code and it grows at the rate of 10% every year. About 4500 lines of codes are added and 1500 lines of code are changed everyday. Initially in 1991, Linux kernel version 0.01 was released with 10239 lines of code.

# A guy named William Della Croce Jr. registered the name Linux and demanded royalty for using its name and mark. However he agreed to handover the trademark to Linus, later.

# The Linux kernel’s official mascot is a penguin named Tux, abbreviation of tuxedo. The idea that Linux had a pet penguin comes from Linus Torvalds himself.

# Linux Torvalds has been honoured by naming an astroid after his name.

# OK, Now the area of application of Linux – U.S. Department of Defense, U.S. Navy Submarine Fleet, Federal Aviation Administration, Tamil Nadu for education purpose, Japan’s bullet trains, traffic control of San Francisco, the New York Stock Exchange, CERN, many air traffic control systems or control of nuclear reactors of submarines and ships, Russia, Brazil and Venezuela for interoperable management , cost efficient and technologically independence, Google, Cisco, Facebook, Twitter, Linked in, Toyota, TiVo, etc, server hosting the website of the White House (Drupal), federal government of Brazil favours Linux operating systems over all others in its PCs. Is Not Linux kernel the most widely ported operating system, running on a great variety of operating systems.

# For those who think Linux can’t do Animation – Oscar-winning visual effects of the Titanic by James Cameron came from machines with Linux and Avatar was the last movie completely developed in 3D Applications on Linux platform using Foss Software. Exclaimed!

# Believe it or not – In 2002, Microsoft had accumulated a $ 421 million cost of fighting the spread of Linux, according to The Register.

# According to a study funded by the European Union, the estimated cost to redevelop the most recent kernel versions would be at $1.14 billion USD – Amazed.

# Microsoft Windows and the Linux kernel can run simultaneously in parallel on the same machine using a software called Cooperative Linux (coLinux).

# IBM choose Linux for what is expected to be the world’s most powerful supercomputer, Sequoia, due in 2011.

Download Youtube videos directly

    

     This is simple youtube trick which will allow you to download any youtube videos without any software or programme and in many different video formats such as mpeg4, 3gp, hd and many more from within the youtube site.

How to do it?

1. First Go to Youtube Homepage.

2.Then select the video you want to download. I will demonstrate with video url given below.

     #http://www.youtube.com/watch?v=8_7s-aaBsBM

3.Now add save or ss or kick before youtube and press enter.

4. After adding any of the above  keyword the above link will become.

     # http://www.ssyoutube.com/watch?v=8_7s-aaBsBM 

     #http://www.saveyoutube.com/watch?v=8_7s-aaBsBM 

     #http://www.kickyoutube.com/watch?v=8_7s-aaBsBM  

 5. Now you will be redirected to a new page from where you can download youtube videos in any format of your choice. You may also download only the soundtrack of the video in mp3 format.

Best Programming Quotations

Best Programming Quotations :

 

 A good programmer is someone who looks both ways before crossing a one-way street.   -- Doug Linder, systems administrator

A most important, but also most elusive, aspect of any tool is its influence on the habits of those who train themselves in its use. If the tool is a programming language this influence is, whether we like it or not, an influence on our thinking habits.   -- Edsger Dijkstra, computer scientist

Being abstract is something profoundly different from being vague... The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise.   -- Edsger Dijkstra

Besides a mathematical inclination, an exceptionally good mastery of one's native tongue is the most vital asset of a competent programmer.   -- Edsger Dijkstra

C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg.   -- Bjarne Stroustrup, developer of the C++ programming language

Commentary: most debugging problems are fixed easily; identifying the location of the problem is hard.   -- unknown

Considering the current sad state of our computer programs, software development is clearly still a black art, and cannot yet be called an engineering discipline.   -- Bill Clinton, former President of the United States

Given enough eyeballs, all bugs are shallow (e.g., given a large enough beta-tester and co-developer base, almost every problem will be characterized quickly and the fix obvious to someone).   -- Eric S. Raymond, programmer and advocate of open source software, from The Cathedral and the Bazaar

Good code is its own best documentation. As you're about to add a comment, ask yourself, 'How can I improve the code so that this comment isn't needed?' Improve the code and then document it to make it even clearer.   -- Steve McConnell, software engineer and author, from Code Complete

Hey! It compiles! Ship it!   -- unknown

Inside every well-written large program is a well-written small program.   -- Charles Antony Richard Hoare, computer scientist

It should be noted that no ethically-trained software engineer would ever consent to write a DestroyBaghdad procedure. Basic professional ethics would instead require him to write a DestroyCity procedure, to which Baghdad could be given as a parameter.   -- Nathaniel S. Borenstein, computer scientist

Managing programmers is like herding cats.   -- unknown

Real programmers don't comment their code. If it was hard to write, it should be hard to understand.   -- unknown

Simplicity is prerequisite for reliability.   -- Edsger Dijkstra

The sooner you start to code, the longer the program will take.   -- Roy Carlson, University of Wisconsin

Weeks of programming can save you hours of planning.   -- unknown

There are only two kinds of programming languages: those people always bitch about and those nobody uses.   -- Bjarne Stroustrup

Hidden Messages in Your Web Browser

Hidden Messages in Your Web Browser :

  

     There is a hidden message in the Web browser you're using right now. Assuming it's Mozilla Firefox. If it isn't, then kindly open Firefox and read that sentence again. We will wait.

Every Mozilla browser includes a special "about" feature that allows you to configure certain sections just by typing "about:whatever" into the address bar. For example, if you type "about:about," you'll see a list of all the menus they offer. Some of the menus are actually cute Easter eggs, like "about:robots," which takes you to a page referencing things like Blade Runner, Futurama, and the eventual annihilation of all mankind.

However, if you type "about:mozilla," perhaps looking to learn a bit more about the browser, you'll come across a red screen with ominous Bible-like text written on it.

What the complete hell? What you've just read is an excerpt from the Book of Mozilla, an ongoing text of apocalyptic literature secretly inserted by Mozilla into each of its Web browsers dating back to when the company worked on AOL's Netscape in 1995. So if you typed "about:mozilla" 17 years ago, you'd see that.

Apparently, each verse is a metaphor for one of the updates Mozilla has released. Hidden developer commentary in the code of the 1998 page confirms that the beast "Mammon" is actually Mozilla's main competitor, Microsoft Internet Explorer. The first verse we showed you says that Mammon has become "naught but a follower," a reference to the fact that the latest editions of Internet Explorer straight up ripped off several features from Mozilla. Among them was the "about:mozilla" page -- if you type that in some versions of Explorer, it takes you to a blank blue screen.

Top Open Source Hacking Tools

 

Nmap : 

Nmap (“Network Mapper”) is a free and open source (license) utility for network discovery and security auditing. Nmap uses raw IP packets in novel ways to determine what hosts are available on the network, what services (application name and version) those hosts are offering, what operating systems (and OS versions) they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics. Nmap homepage.  

Wireshark :

Wireshark is a network protocol analyzer. It lets you capture and interactively browse the traffic running on a computer network. Wireshark homepage.

Nikto2 :

Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 6400 potentially dangerous files/CGIs, checks for outdated versions of over 1200 servers, and version specific problems on over 270 servers. It also checks for server configuration items such as the presence of multiple index files, HTTP server options, and will attempt to identify installed web servers and software. Nikto2 homepage.

Ettercap :

Ettercap is a comprehensive suite for man in the middle attacks. It features sniffing of live connections, content filtering on the fly and many other interesting tricks. It supports active and passive dissection of many protocols and includes many features for network and host analysis. ettercap homepage.

NexPose Community edition :

The Nexpose Community Edition is a free, single-user vulnerability management solution. Nexpose Community Edition is powered by the same scan engine as Nexpose Enterprise and offers many of the same features. Nexpose homepage.

Ncat :

Ncat is a feature-packed networking utility which reads and writes data across networks from the command line. Ncat was written for the Nmap Project as a much-improved reimplementation of the venerable Netcat. It uses both TCP and UDP for communication and is designed to be a reliable back-end tool to instantly provide network connectivity to other applications and users. Ncat will not only work with IPv4 and IPv6 but provides the user with a virtually limitless number of potential uses. ncat homepage.

 Kismet :

Kismet is an 802.11 layer2 wireless network detector, sniffer, and intrusion detection system. Kismet will work with any wireless card which supports raw monitoring (rfmon) mode, and (with appropriate hardware) can sniff 802.11b, 802.11a, 802.11g, and 802.11n traffic. Kismet also supports plugins which allow sniffing other media such as DECT. kismet homepage.

w3af :

w3af is a Web Application Attack and Audit Framework. The project’s goal is to create a framework to find and exploit web application vulnerabilities that is easy to use and extend. w3af homepage.

Linux shell commands tips and tricks

Linux shell commands tips and tricks:

 
     Keep in mind that for some commands you will need to install additional software on your Linux distribution.

SSH debug mode:
    $ ssh -vvv user@ip_address   

SSH with pem key:

     $ ssh user@ip_address -i key.pem    

Create war file:

     $ jar -cvf name.war file    

Test disk read speed:

     $ hdparm -Tt /dev/sda    

Get md5 hash from text:

     $ echo -n "text" | md5sum    

Check xml syntax:

     $ xmllint --noout file.xml    

Extract tar.gz in new directory:

     $ tar zxvf package.tar.gz -C new_dir    

Get HTTP headers with curl:

     $ curl -I http://www.example.com      

Modify timestamp of some file or directory (YYMMDDhhmm):

     $ touch -t 0712250000 file    

Download from ftp using wget:

     $ wget -m ftp://username:password@hostname    

Generate random password (16 char long in this case):

     $ LANG=c < /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c${1:-16};echo;    

Quickly create a backup of a file:

     $ cp some_file_name{,.bkp}    

Access Windows share:

     $ smbclient -U "DOMAIN\user" //dc.domain.com/share/test/dir    

Run command from history (here at line 200):

     $ !200    

Unzip to directory:

     $ unzip package_name.zip -d dir_name    

Show free RAM in MB:

     $ free -m | grep cache | awk '/[0-9]/{ print $4" MB" }'    

Git clone specific branch (master):

     $ git clone git@github.com:name/app.git -b master    

Git switch to another branch (develop):

     $ git checkout develop    

Git delete branch (mybranch):

     $ git branch -d mybranch    

Git delete remote branch:

     $ git push origin :branchName    

Git push new branch to remote:

     $ git push -u origin mynewfeature    

List all supported kill signals:

     $ kill -l    

Installing Lua and Luarocks in CentOS

Installing Lua and Luarocks in CentOS:

     There seems to be something wrong with CentOS' lua package (version 5.1.4). After installing lua via yum, compiling luarocks in /usr/local/src/ and running the luarocks command, you will end up with the following error:

The issue seems to persist even in CentOS 6. So we suggest building lua and luarocks directly from the source after some OS library dependencies are met:

     # yum install gcc gcc-c++ kernel-devel    
     # yum install readline-dev                         
     # yum install ncurses-devel.i386               

Proceed to download and compile lua:

     # wget http://www.lua.org/ftp/lua-5.1.4.tar.gz     
     # tar zxvf lua-5.1.4.tar.gz                                     
     # cd lua-5.1.4                                                       
     # make linux                                                          

Download and install luarocks:

     # wget http://luarocks.org/releases/luarocks-2.0.6.tar.gz    
     # tar zxvf luarocks-2.0.6.tar.gz                                             
     # cd luarocks-2.0.6                                                               
     # ./configure                                                                          
     # make                                                                                  
     # make install                                                                        

This should help you have luarocks properly installed and ready to fetch lua modules from the repo. Have fun!