Stop the Cursor from Blinking

I have nothing against a blinking cursor myself, but some find it distracting. To stop Ubuntu’s cursor from blinking, open gconf-editor, navigate to /desktop/gnome/interface, and remove the check from cursor_blink. Then log out and back in again. Note that Evolution appears to ignore this setting, but most other applications will now have a still cursor.

Alternatively, by changing the value in cursor_blink_time, you can simply make it blink more slowly. A value of 5000 equates to five seconds—each unit is 1 ms. Be aware that a setting such as 5000 means the cursor will be visible for five seconds at a time and then invisible for the same length of time.

Closely Monitor the Power Consumption of a Laptop

Run gnome-power-statistics, and you’ll see a graph of the exact power usage of your computer over the time since it booted up (provided your computer’s hardware supports it). Try boosting the brightness of your screen or loading programs, and see how much of a drain they can be!

Switch Monitor Resolutions with a Single Mouse Click

If you have an external monitor or projector you occasionally attach to a notebook computer, you might be used to switching resolutions on a regular basis. Unlike with Windows, this isn’t just a right-click procedure—you must navigate the System→Preferences menu.

A good solution is to use Synaptic to search for and install resapplet. For some reason, although it’s officially a GNOME applet, resapplet doesn’t appear on the standard applet list. Instead, it must be configured to start at login. To do this, click System→Preferences→Sessions, ensure the Startup Programs tab is selected, and click the Add button. In the Name and Command fields of the dialog box that appears, type resapplet. Leave the Comment field blank. Then close the dialog box, and log out and back in again.

The new icon will then appear beside Network Monitor in the notification area. Clicking it will reveal a list of possible resolutions from which you can choose. Incidentally, it should be possible to instantly step up and down resolutions by pressing Ctrl+Alt and tapping the +/- keys on the numeric keypad. Unfortunately, this doesn’t work on Ubuntu systems because of the way the graphical subsystem is configured. It may work on other Linux systems, however.

Add Cool New Visualizations to Totem / Rhythm Box

Both Totem and Rhythm Box include a funky animation that appears during music playback. Animations such as this are known as visualizations, but out of the box Ubuntu includes only one, rather than the hundreds found on the likes of Mac OS or Windows media players. However, you can add more to Ubuntu, for use in both Totem and Rhythm Box, by using Synaptic to search for and install the libvisual-0.4- plugins package.

Once the package has been installed, to change the visualization in Totem that appears when a music track is playing, click Edit→Preferences, select the Display tab in the dialog box that appears, and make your choice from the Type of visualization drop-down list. Your choice will take effect immediately,so drag the Preferences dialog box out of the way to preview it.

In Rhythm Box, click View→Visualization to start the animation, and then select from the drop-down list beneath the visualization.

See (and Reuse) the Most Recently Typed Commands

The command line includes a powerful history feature that can make life much easier. To see the recently typed commands, type history. This simply dumps to the screen a hidden file in your /home directory called .bash_history where up to 1,000 commands are recorded. Because this list will scroll off the screen when listed, it’s a good idea to pipe the output into a text reader, such as less:

$ history|less

To reuse one of your commands, at the command prompt type an exclamation mark (!; known as a bang in bash-speak) and then the number alongside the entry in the history list.For example,on my system, I noted when viewing the history list that the command cp /etc/ fstab ~/Desktop was command 591. To use it again, I typed !591 at the command prompt. If you ever need to simply repeat a command you’ve just used, type two exclamation marks—!!.

To actively rifle through your command history, hit Ctrl+r and then start typing the command in which you’re interested.The prompt will “auto complete” as you type. To use the command, hit Enter. To edit it before using it,hit Esc, and then make your changes.

Hitting the up and down cursor keys will also let you move through the most recently typed commands. Just hit Enter when you find the one youwanttoreuse.

Set Any Picture as Wallpaper with a Single Click

The easiest way of setting your own picture as a desktop wallpaper is to click and drag the image to the desktop using the middle mouse button (if the image is already on the desktop, then click and drag it a few inches to the left/right). On most modern mice, the middle mouse button is the scroll wheel, which also doubles as a third mouse button. On the menu that appears when you release the button, click Set as Background.

If that sounds a little too unorthodox for you (it can be hard to use the middle mouse button), you can also use Synaptic to install the nautilus-wallpaper package, which adds a simple Set as Wallpaper option to the menu that appears when you right-click an image file. After installation, you’ll need to log out and then in again before the option becomes visible.

Network app for Linux

Networking is a huge part of Linux and in order to be adept at it, one needs to know network apps. Here are a few that will tickle the brain cells and keep you sharp when the terminals are running.

Netscape

If you have the netscape installation, which you should, then, try running netscape on the X terminal. The problem though is that the versions of Netscape available right now are quite large and faulty. When you are not connected to the Internet, Netscape often stops working completely and looks as if it has hanged.

netscape -display host:0.0

If the machine that you’re working on has the permission to access and display on the ‘host’ machine, then run netscape on the one you are working on and transfer the output onto the machine called ‘host’.

lynx file.html

This is used when you are on the text mode and want to browse the internet from it, or if you want to view an html file.

pine

Local mail is mail that is sent by someone on your network to your computer. Pine reads this mail for you. You can also use Elm for this. You have Netscape for reading your email otherwise.

elm

As mentioned above, this does the same job as pine.

mutt

Quite aptly named, this is a fast and very useful mail reader. It is a basic app though.

mail

This is also a basic tool for emails and the commands mentioned above are much better.

licq

Icq clients are instant messaging clients. While this one is a good option, you can also go for kxicq. Older Linux distributions do not have icq clients installed in them.

talk username1

This is a network command that is used to talk to other users who are logged into the machine that you’re working on. You can use the command talk username1@machinename if you want to talk to someone on a different computer. Accepting a command is done through the ‘talk username2’. Rejecting a conversation is done through ‘mesg n’.

mc

Mc stands for Midnight Commander. It is used to launch the file manager.

telnet server

You us this command when you want to connect to a different machine using the TELNET protocol. One must have a login on the remote machine they are trying to connect to.

rlogin server

It stands for remote login and allows you to log into a remote machine. It uses the login id and password from your current session automatically and asks for a password in case the login fails.

rsh server

This does the same thing as the above command. It stands for remote shell.

ftp server

This command is useful for copying files to a remote machine or from it. In order to add extra features for graphical user interface, you can use ncftp.

Linux Distribution

A Linux distribution is a collection of (usually open source) software on top of a Linux kernel. A distribution (or short, distro) can bundle server software, system management tools, documentation and many desktop applications in a central secure software repository. A distro aims to provide a common look and feel, secure and easy software management and often a specific operational purpose.

Let's take a look at some popular distributions. 

1.Red Hat

Red Hat is a billion dollar commercial Linux company that puts a lot of effort in developing Linux. They have hundreds of Linux specialists and are known for their excellent support. They give their products (Red Hat Enterprise Linux and Fedora) away for free. While Red Hat Enterprise Linux (RHEL) is well tested before release and supported for up to seven years after release, Fedora is a distro with faster updates but without support.

2.Ubuntu

Canonical started sending out free compact discs with Ubuntu Linux in 2004 and quickly became popular for home users (many switching from Microsoft Windows). Canonical wants Ubuntu to be an easy to use graphical Linux desktop without need to ever see a command line. Of course they also want to make a profit by selling support for Ubuntu.

3.Debian

There is no company behind Debian. Instead there are thousands of well organised developers that elect a Debian Project Leader every two years. Debian is seen as one of the most stable Linux distributions. It is also the basis of every release of Ubuntu. Debian comes in three versions: stable, testing and unstable. Every Debian release is named after a character in the movie Toy Story.

4. SUSE 

it is a paid version although the openSUSE version can be downloaded for free.

5. Linux Mint 

It claims to be the fourth most popular OS and it is easy to use with 30,000 packages.

6. Slackware 

It was released in 1993 making it one of the oldest Linux distributions. It is majorly dependent on command-line tools.

7. Gentoo 

First released in 2002, it offers "extreme configurability, performance and a top-notch user and developer community." It works on the Portage package management system which has over 10,000 different applications.

8. <"http://www.archlinux.org/">Arch Linux 

Arch’s simplistic design makes it a favorite among long-time Linux users. It installs a minimal base system and offers many options for customization.

9. Fedora 

This is free community version. It also has the standard desktop download which is available in many specialized versions as stated on datamation.com.

10. openSUSE

This free community version can be used on a desktop, laptop or server and can be installed or run live from a CD or USB drive. 

Distributions Based on Ubuntu-

11. Kubuntu

Kubuntu is a Ubuntu fork using the KDE desktop in place of the Unity desktop. 

12. Lubuntu

Lubuntu is lighter, faster, and consumes less energy making it a good choice for mobile devices like netbooks.

13. Xubuntu

This version of Ubuntu uses Xfce desktop environment for both desktop and server versions.

14. Edubuntu 

This is suited to meet the needs of schools.

15. Easy Peasy

Designed for use on netbooks, it has millions of users in more than 166 countries.

16. Zentyal

This is available for free, paid and supported versions. It is a Ubuntu-based small business server acting as a gateway, infrastructure manager, unified threat manager, office server and/or unified communication server. 

17. NewSense 

This has support by the Free Software Foundation and is based on Ubuntu with minor changes which include removal of non-free firmware. 

18. Pinguy OS 

This is for new Linux users. Pinguy OS makes it easy to search and use the programs average users. It also has a DVD version for $5.99.

19. Bodhi Linux 

This is focused on user choice and minimalism. It makes use of the enlightenment desktop environment and a "software store" making it easy to locate and install the open source applications.

20. MoonOS 

This is developed in Cambodia (English is supported) and based on Ubuntu. It has a different file hierarchy system and appshell framework. 

Distributions Based on Debian

21. MEPIS 

This is also called simplyMEPIS and is especially popular with new Linux users. You can download it for free or buy a CD that will make testing and installation of software easy. 

22. CrunchBang 

It is a lightweight distribution working on Debian.

23. Knoppix 

It is good for newbies and is an easy-to-use distribution based on Debian. It is available in CDs for less than two bucks.

24. DreamLinux 

This can be installed on your desktop as well as run from a USB drive. It installs the Xfce desktop environment by default and supports Gnome.

Distributions Based on Red Hat/Fedora

25. Mandriva 

It is a publicly traded French company and has over 3 million users worldwide. It has several editions which include desktop and server, paid and unpaid, and a unique Instant On version that boots up with minimal functionality in less than 10 seconds.

26. CentOS

This is the short form for Short for "Community ENTerprise Operating System". It is based on Red Hat code. It's used in 30 percent of Linux-based Web servers.

27. Scientific Linux 

This is aimed at preventing scientists at each of these different institutions from recreating a Linux distribution to meets their needs.

28. Fusion 

It offers multimedia support and has an interesting look and feel. This is ideal for more advanced Linux users.

Distributions Based on Mandriva

29. Unity 

It is built to offer developers or advanced Linux users certain modular pieces that can be used for creating customized distribution.

30. Mageia 

This is a community-driven fork with some ownership changes at the company that owns the Mandriva project. It's currently in beta stages and due for release in a few weeks time.

Distributions Based on Slackware

31. ZenWalk

This has become better over time into a modern, fast, lightweight distribution that's simple to use. This is present in five versions - standard, core, live, Gnome and Openbox.

32. Vector Linux 

It is availablefor free download as well as in a supported "deluxe" edition.

33. Frugalware 

This is ideal for users who don’t fear command line, it has certain graphical tools which are with simplicity in mind.

34. Salix OS 

This is available in four different versions for the Xfce, LXDE, Fluxbox and KDE desktop environments.

Distributions Based on Arch Linux

35. Chakra 

This is based on ArchLinux and uses KDE desktop. 

36. ArchBang

This variant utilizes the Openbox Window Manager and is fast as well as lightweight.

37. Sabayon 

This is based on Gentoo and supports KDE, Gnome, LXDE and Xfce desktop environments.

Distributions Based on Cloud Computing 

38. Joli OS 

This can be installed within 10 minutes and is optimized for cloud computing applications. 

39. Peppermint 

It is created for both cloud and Web apps. It is based on Lubuntu.

Lightweight Distributions

40. aLinux 

Earlier it was known as Peanut Linux. It is designed to be quick as well as multimedia-friendly. 

41. DSL 

It is a small OS at just 50MB. It is very fast and runs on older PCs. It can fit onto small USB drives and business card CDs.

42. Tiny Core Linux 

Among the smallest ones it weighs just 10MB in its GUI version. Its command line version, the Micro Core, is even smaller.

43. Puppy Linux 

It is small and quick and can be installed on a USB thumb drive that you can carry with you. It occupies 100 MB and gets booted in less than a minute. It runs from RAM for maximum speed.

Windows-Like Distributions

44. Zorin OS 

It was meant to look and feel as much like Windows as possible. It is faster and doesn not have many bugs. This is available in both free and paid versions.

45. Ylmf OS 

Its interface is similar in appearance to Windows. It's available in either Chinese or English and based on Ubuntu.

Other Distributions

46. GoboLinux 

This does not make use of the Unix Filesystem Hierarchy Standard but keeps each program in its own sub-directory in the Program directory. 

47. PCLinuxOS 

It is easy to use and can run a Live CD or installed on a desktop or laptop. It can support seven different desktops, including KDE, Gnome, Enlightenment, XFCE, LXDE, and others.

48. MeeGo 

It is based on Intel's Moblin and Nokia's Maemo. It can be used on netbooks and other mobile devices as well. 

49. Chrome OS/Chromium OS 

The "Chromium OS" is the open source version for developers and "Chrome OS" is the operating system that Google plans to include on netbooks for end users. 

50. Musix GNU+Linux 

Musix is made for multi-media enthusiasts especially those involved in audio editing. 

Which to choose ?

When you are new to Linux in 2012, go for the latest Ubuntu or Fedora. If you only want to practice the Linux command line then install one Ubuntu server and/or one CentOS server (without graphical interface).

         redhat.com

         ubuntu.com

         debian.org

         centos.org

         distrowatch.com

Linux history

All modern operating systems have their roots in 1969 when Dennis Ritchie and Ken Thompson developed the C language and the Unix operating system at AT&T Bell Labs. They shared their source code (yes, there was open source back in the Seventies) with the rest of the world, including the hippies in Berkeley California. By 1975, when AT&T started selling Unix commercially, about half of the source code was written by others. The hippies were not happy that a commercial company sold software that they had written; the resulting (legal) battle ended in there being two versions of Unix in the Seventies : the official AT&T Unix, and the free BSD Unix.

In the Eighties many companies started developing their own Unix: IBM created AIX, Sun SunOS (later Solaris), HP HP-UX and about a dozen other companies did the same. The result was a mess of Unix dialects and a dozen different ways to do the same thing. And here is the first real root of Linux, when Richard Stallman aimed to end this era of Unix separation and everybody re-inventing the wheel by starting the GNU project (GNU is Not Unix). His goal was to make an operating system that was freely available to everyone, and where everyone could work together (like in the Seventies). Many of the command line tools that you use today on Linux or Solaris are GNU tools.

The Nineties started with Linus Torvalds, a Swedish speaking Finnish student, buying a 386 computer and writing a brand new POSIX compliant kernel. He put the source code online, thinking it would never support anything but 386 hardware. Many people embraced the combination of this kernel with the GNU tools, and the rest, as they say, is history.

Today more than 90 percent of supercomputers (including the complete top 10), more than half of all smartphones, many millions of desktop computers, around 70 percent of all web servers, a large chunk of tablet computers, and several appliances (dvd- players, washing machines, dsl modems, routers, ...) run Linux. It is by far the most commonly used operating system in the world.

Linux kernel version 3.2 was released in January 2012. Its source code grew by almost two hundred thousand lines (compared to version 3.1) thanks to contributions of over 4000 developers paid by about 200 commercial companies including Red Hat, Intel, Broadcom, Texas Instruments, IBM, Novell, Qualcomm, Samsung, Nokia, Oracle, Google and even Microsoft. 

Downloading Kali Linux

Downloading Kali Linux

Download Official Kali Images

Official Kali Linux Images

ISO Files

Kali Linux is available as a bootable ISO in both 32 and 64-bit formats.

VMware Images

Kali is available as a pre-made VMware virtual machine with VMware Tools installed. The VMware image is available in a 32-bit PAE format.

ARM Images

Due to the nature of the ARM architecture, it is not possible to have a single image that will work across all ARM devices. We have Kali Linux ARM images available for the following devices:

• rk3306 mk/ss808 
• Raspberry Pi 
• ODROID-U2/X2 
• MK802/MK802 II 
• Samsung Chromebook

Download Link: http://www.kali.org/downloads/

Verifying SHA1 Checksums of Downloaded Images

When you download an image, be sure to download the SHA1SUMS and SHA1SUMS.gpg files that are next to the downloaded image (i.e. in the same directory on the server).

 Ensure the Origin of the SHA1SUMS File

 

Before verifying the checksums of the image, you must ensure that the SHA1SUMS file is the one generated by Kali. That’s why the file is signed by Kali’s official key with a detached signature in SHA1SUMS.gpg. Kali’s official key can be downloaded in one of two ways:

$ wget -q -O - http://archive.kali.org/archive-key.asc | gpg --import 

# or 

$ gpg --keyserver subkeys.pgp.net --recv-key 44C6513A8E4FB3D30875F758ED444FF07D8D0BF6

Once you have downloaded both SHA1SUMS and SHA1SUMS.gpg, you can verify the signature as follows:

$ gpg --verify SHA1SUMS.gpg SHA1SUMS 

gpg: Signature made Thu Mar  7 21:26:40 2013 CET using RSA key ID 7D8D0BF6 

gpg: Good signature from "Kali Linux Repository <devel@kali.org>"

If you don’t get that “Good signature” message or if the key ID doesn’t match, then you should stop the process and review whether you downloaded the images from a legitimate Kali mirror. If the SHA1SUMS file is the one provided by Kali, then you can verify that the image downloaded has the required checksum. You can either generate the checksum and do a manual comparison with what’s listed in SHA1SUMS or use a tool that knows how to verify those checksums. 

 TODO: explain how to use GPG on OS X and Windows. See https://www.torproject.org/docs/verifying-signatures.html.en for inspiration.

Verifying SHA1 Checksums on Linux

 With a manual comparison:

$ sha1sum kali-linux-1.0-i386.iso 

796e32f51d1bf51e838499c326c71a1c952cc052  kali-linux-1.0-i386.iso 

$ grep kali-linux-1.0-i386.iso SHA1SUMS 

796e32f51d1bf51e838499c326c71a1c952cc052  kali-linux-1.0-i386.iso

By using sha1sum -c:

grep kali-linux-1.0-i386.iso SHA1SUMS | sha1sum -c 

kali-linux-1.0-i386.iso: OK

Verifying SHA1 Checksums on OSX

With a manual comparison:

$ shasum kali-linux-1.0-i386.iso 

796e32f51d1bf51e838499c326c71a1c952cc052  kali-linux-1.0-i386.iso 

$ grep kali-linux-1.0-i386.iso SHA1SUMS 

796e32f51d1bf51e838499c326c71a1c952cc052  kali-linux-1.0-i386.iso

Verifying SHA1 Checksums on Windows

Windows does not have the native ability to calculate SHA1 checksums so you will need a utility such asFree MD5 SHA1 verifier to verify your download.

Download Link: http://www.keylack.com/free-md5-sha1-verifier.html

Process Management Linux Commands

Process Management Linux Commands

• ps – report a snapshot of the current processes                                      

Usage: ps [OPTION]                                                                          

eg. ps,  ps ­-el   

• bg – make a foreground process to run in background                        

Usage: type 'ctrl+z'  and then 'bg <job id>' 

 • fg – to make background process as foreground process                      

Usage: fg [jobid]

 • jobs – displays the names and ids of background jobs                         

Usage: jobs

• kill – to kill a process(using signal mechanism)                                     

Usage: kill [OPTION] pid                                                                  

eg. kill -­9 2275 

Archival

• tar – to archive a file                                                                              

Usage: tar [OPTION] DEST SOURCE                                           

eg. tar -­cvf /home/archive.tar /home/original                                         

     tar ­-xvf /home/archive.tar 

• zip – package and compress (archive) files                                           

Usage: zip [OPTION] DEST SOURSE                                           

eg. zip original.zip original

• unzip – list, test and extract compressed files in a ZIP archive           

Usage: unzip filename         

eg. unzip original.zip

Network

• ssh – SSH client (remote login program)                                         

“ssh is a program for logging into a remote machine and for executing commands on a remote machine”        

Usage: ssh [options] [user]@hostname    

eg. ssh -­X guest@10.105.11.20 

• scp – secure copy (remote file copy program)                                       

“scp copies files between hosts on a network”          

Usage: scp [options] [[user]@host1:file1] [[user]@host2:file2]  

eg. scp file1.txt guest@10.105.11.20:~/Desktop/

File Systems

• fdisk – partition manipulator                                                        

eg. sudo fdisk ­-l 

• mount – mount a file system                                                       

Usage: mount -­t type device dir                                               

eg. mount /dev/sda5 /media/target                                       

• umount – unmount file systems                                                  

Usage: umount [OPTIONS] dir | device...                               

eg.  umount /media/target 

• du – estimate file space usage                                                                 

Usage:  du [OPTION]... [FILE]...                                                      

eg. du      

• df – report filesystem disk space usage                                                 

Usage: df [OPTION]... [FILE]...                                                        

eg. df     

• quota – display disk usage and limits                                                   

Usage: quota [OPTION]                                                                    

eg. quota ­-v    

Advanced Commands

• reboot – reboot the system                                                             

Usage: reboot [OPTION]                                                       

eg. reboot                                                                                            

• poweroff – power off the system                                                   

Usage: poweroff [OPTION]      

eg. poweroff

• sed–  stream editor for filtering and transforming text               

Usage: sed [OPTION] [input­file]...                                        

eg. sed 's/love/hate/g' loveletter.txt 

• awk– pattern scanning and processing language                        

eg.  awk ­-F: '{ print $1 }' sample_awk.txt 

• find – search for files in a directory hierarchy                                       

Usage: find [OPTION] [path] [pattern]                                             

eg. find ­name file1.txt 

• locate – find or locate a file      

Usage: locate [OPTION]... FILE...      

eg. locate file1.txt

Editor commands

• kate – KDE Advanced Text Editor                                                         

Usage:  kate [options][file(s)]                                                            

eg. kate file1.txt file2.txt                                                                

• vim – Vi Improved, a programmers text editor                                       

Usage: vim [OPTION] [file]...                                                           

eg. vi hello.c 

• gedit ­ A text Editor. Used to create and edit files.                                          

Usage: gedit [OPTION] [FILE]...                                                      

eg. gedit        

System Administration Linux Commands

System Administration Linux Commands

• chmod – change file access permissions                                         

Usage: chmod [OPTION] [MODE] [FILE]                                      

eg. chmod 744 calculate.sh    

• chown – change file owner and group                                                     

Usage: chown [OPTION]... OWNER[:[GROUP]] FILE...               

eg. chown remo myfile.txt  

•  su –  change user ID or become super-­user                              

Usage: su [OPTION] [LOGIN]                                                 

eg. su remo, su 

• passwd – update  a user’s authentication tokens(s)                   

Usage: passwd [OPTION]                                                       

eg. passwd 

• who – show who is logged on                                                     

Usage: who [OPTION]                                                            

eg. who , who ­-b , who -q

Linux File Permissions

Linux File Permissions 

• 3 types of file permissions – read, write, execute 

• 10 bit format from 'ls -­l' command 

     1           2 3 4      5 6 7     8 9 10             

   file type    owner     group    others 

eg.  drwxrw­-r--­­  means owner has all three permissions,group has read and write, others have only read              permission.

• read permission = 4, write = 2, execute =1 

eg. rwxrw-­r­­--   = 764 

       673    =   rw-­rwx­-wx

Text Processing Linux Commands

Pattern

A Pattern is an expression that describes a set of   strings which is used to give a concise description  of a set, without having to list all elements.

eg.  ab*cd matches anything that starts with ab and ends with cd etc.

 ls *.txt – prints all text files

Text Processing

• cat – 

concatenate files and print on the standard output

Usage:

cat [OPTION] [FILE]... 

eg. cat file1.txt file2.txt 

      cat -­n file1.txt 

• echo – display a line of text   

 

Usage: echo [OPTION] [string] ... 

eg. echo I love India

Linux File Handling Commands

Linux File Handling Commands

MAN Command 

 • man <command>  ­ shows all information about the  command  

• <command> --­­help  ­ shows the available options  for that command  

File Handling commands 

• mkdir – make directories                                                                           

  Syntax: mkdir [OPTION] DIRECTORY...

  eg. mkdir divakar

• ls – list directory contents                                                                          

Syntax: ls [OPTION]... [FILE]...                                                        

eg. ls, ls ­l, ls  divakar

• cd – changes directories                                                                          

Syntax: cd [DIRECTORY]  

eg. cd divakar

• pwd ­  print name of current working directory                                      

Syntax: pwd    

• vim – Vi Improved, a programmers text editor                                       

Syntax: vim [OPTION] [file]...                                                           

eg. vim file1.txt  

• cp – copy files and directories                                                        

Syntax: cp [OPTION]... SOURCE DEST                               

eg. cp sample.txt sample_copy.txt                                              

      cp sample_copy.txt target_dir   

•mv – move (rename) files                                                            

Syntax: mv [OPTION]... SOURCE DEST                            
eg. mv source.txt target_dir                                                        

       mv old.txt new.txt

• rm ­ remove files or directories                                               

Syntax: rm [OPTION]... FILE...   

eg. rm file1.txt , rm -­rf some_dir  

• find – search for files in a directory hierarchy                         

Usage: find [OPTION] [path] [pattern]                             

eg. find file1.txt, find -­name file1.txt 

• history – prints recently used commands                                   

Usage: history 

KALI -LINUX

Introduction to Kali Linux

What is Kali Linux ?

Kali Linux is an advanced Penetration Testing and Security Auditing Linux distribution.

Kali Linux Features

Kali is a complete re-build of BackTrack Linux, adhering completely toDebian development standards. All-new infrastructure has been put in place, all tools were reviewed and packaged, and we use Git for our VCS.

More than 300 penetration testing tools: After reviewing every tool that was included in BackTrack, we eliminated a great number of tools that either did not work or had other tools available that provided similar functionality. 

Free and always will be: Kali Linux, like its predecessor, is completely free and always will be. You will never, ever have to pay for Kali Linux. 

Open source Git tree: We are huge proponents of open source software and ourdevelopment tree is available for all to see and all sources are available for those who wish to tweak and rebuild packages. 

FHS compliant: Kali has been developed to adhere to theFilesystem Hierarchy Standard, allowing all Linux users to easily locate binaries, support files, libraries, etc. 

Vast wireless device support: We have built Kali Linux to support as many wireless devices as we possibly can, allowing it to run properly on a wide variety of hardware and making it compatible with numerous USB and other wireless devices. 

Custom kernel patched for injection: As penetration testers, the development team often needs to do wireless assessments so our kernel has the latest injection patches included. 

Secure development environment: The Kali Linux team is made up of a small group of trusted individuals who can only commit packages and interact with the repositories while using multiple secure protocols. 

GPG signed packages and repos: All Kali packages are signed by each individual developer when they are built and committed and the repositories subsequently sign the packages as well. 

Multi-language: Although pentesting tools tend to be written in English, we have ensured that Kali has true multilingual support, allowing more users to operate in their native language and locate the tools they need for the job. 

Completely customizable: We completely understand that not everyone will agree with our design decisions so we have made it as easy as possible for our more adventurous users to customize Kali Linux to their liking, all the way down to the kernel. 

ARMEL and ARMHF support: Since ARM-based systems are becoming more and more prevalent and inexpensive, we knew thatKali’s ARM support would need to be as robust as we could manage, resulting in working installations for bothARMEL and ARMHF systems. Kali Linux has ARM repositories integrated with the mainline distribution so tools for ARM will be updated in conjunction with the rest of the distribution. Kali is currently available for the following ARM devices:

•  rk3306 mk/ss808 
• Raspberry Pi 
• ODROID U2/X2 
• Samsung Chromebook 
• EfikaMX 
• Beaglebone Black 
• CuBox 
• Galaxy Note 10.1

Kali is specifically tailored to penetration testing and therefore, all documentation on this site assumes prior knowledge of the Linux operating system.

Should I Use Kali Linux?

Differences Between Kali Linux and Debian

Kali Linux is geared towards professional penetration testing and security auditing. As such, several core changes have been implemented in Kali Linux which reflect these needs:

1. Single user, root access by design: Due to the nature of security audits, Kali linux is designed to be used in a “single, root user” scenario.

2. Network services disabled by default: Kali Linux contains sysvinit hooks which disable network services by default. These hooks allow us to install various services on Kali Linux, while ensuring that our distribution remains secure by default, no matter what packages are installed. Additional services such as Bluetooth are also blacklisted by default.

3. Custom Linux kernel: Kali Linux uses an upstream kernel, patched for wireless injection.

Is Kali Linux Right For You?

As the distribution developers, one would likely expect us to recommend that everyone use Kali Linux. The fact of the matter is however, that Kali is a Linux distribution specifically geared towards professional penetration testing and security auditing and as such, it is NOT a recommended distribution for those unfamiliar with Linux.

In addition, misuse of security tools within your network, particularly without permission, may cause irreparable damage and result in significant consequences.

If you are looking for a Linux distribution to learn the basics of Linux and need a good starting point, Kali Linux is not the ideal distribution for you. You may want to begin with Ubuntu or Debian instead.

Kali Linux Default Passwords

Kali Linux Default root Password is toor

Default root Password

During installation, Kali Linux allows users to configure a password for the root user. However, should you decide to boot the live image instead, the i386, amd64, VMWare and ARM images are configured with the default root password – “toor“, without the quotes.