Welcome back, my dear friends!
For
those of you who've never used Linux (specially backtrack), I dedicate
the next few posts (tutorials) on the basics of Linux with an emphasis
on the skills you need for hacking. So, let's open up Backtrack. (To know the way of installing backtrack 5 click here )
Open a terminal
To become proficient in Linux, you MUST
master the terminal. Many things can be done now in the various Linux
distributions by simply pointing and clicking, similar to Windows or Mac
OS, but the expert hacker must know how to use the terminal to run most
of the hacking tools.
So, let's open a terminal by clicking on the terminal icon on the bottom
bar.
If you've ever used the command prompt in
Windows, the Linux terminal is similar, but far more powerful. Unlike
the Windows command prompt, you can do EVERYTHING in Linux from the terminal and control it more precisely than in Windows.
It's important to keep in mind that unlike Windows, Linux is
case-sensitive. This means that "Sivarathan" is different from
"sivarathan" which is different from "SIVARATHAN". Those who are new to
Linux often find this challenging, so try to keep this in mind.
Examine the directory structure
Let's start with some basic Linux. Many
beginners get tripped up by the structure of the file system in Linux.
Unlike Windows, Linux's file system is not linked to a physical drive
like in Windows, so we don't have a c:\ at the beginning of our Linux file system, but rather a /.
The forward slash (/)
represents the "root" of the file system or the very top of the file
system. All other directories (folders) are beneath this directory just
like folders and sub-folders are beneath the c:\ drive.
To visualize the file system, let's take a look at this diagram below.
It's important to have a basic understanding of this file structure
because often we need to navigate through it from the terminal without
the use of a graphical tool like Windows Explorer.
A couple key things to note in this graphical representation:
- The /bin directory is where binaries are stored. These are the programs that make Linux run.
- /etc is generally where the configuration files are stored. In Linux, nearly everything is configured with a text file that is stored under /etc.
- /dev directory holds device files, similar to Windows device drivers.
- /var is generally where log files, among other files, are stored.
Using pwd
When we open a terminal in BackTrack, the default directory we're in is
our "home" directory. As you can see from the graphic above, it's to the
right of the "root" directory or one level "below" root. We can confirm
what directory we are in by typing:
- bt > pwd
pwd stands for "present working directory" and as you can see, it returns "/root" meaning we're in the root users directory (don't confuse this with the top of the directory tree "root." This is the root users directory).
pwd is a handy command to remember as we can use it any time to tell us where we are in the directory tree.
Using cd command
We can change the directory we're working in by using the cd (change directory) command. In this case, let's navigate "up" to the top of the directory structure by typing:
- bt > cd ..
The cd command followed by the double dots (..) says, "move me up one level in the directory tree." Notice that our command prompt has changed and when we type pwd we see that Linux responds by telling us we are in the "/" or the top of the directory tree (or the root directory).
Using whoami Command
In our last lesson of this tutorial, we'll use the whoami command. This command will return the name of the user we're logged in as. Since we're the root user, we can log in to any user account and that user's name would be displayed here.
- bt > whoami
I thing this is enough for today in our following posts I will continue
to give you the basics of backtrack that you'll need to be a pro hacker,
so keep coming back! Bye from SoftQQ
If you have any doubt feel free to ask in the comment section :) :) :) :) :)
