Classification of commands

Shell Commands can be classified into 3 types

1. Simple Commands
2. Complex Commands
3. Compound Commands

Simple Commands

A simple command is one that you can execute by just giving its name at the prompt.

It looks like something below

$Command

Here the, command is the name of the command which you want to execute. Simple command in Unix can be small command like the following

1. who

2. date

3. ls

4. pwd

etc.

Complex Commands

Complex command follows the following syntax

$ Command arg1 arg2 .... .... ... argN

Here the command is the name of the command you want to execute and arg1 through argn are the arguments you want to give to the command.

The complex command can be commands like these

1. echo "Hello World"

2. who am i

to be continued 

The "Hello world"

Prerequisites: http://unixcookeries.blogspot.com/2011/09/terminal.html

Now that we are inside the terminal ready to explore the possibility of simple and powerful tool. Which gives you access to communicate with the Kernel the heart of U/Li NUX. Now lets start exploring it.

Some thing got to tell you before that the $or # or something is what you will be having before(I mean on the left side) of your cursor. That is where the command should be entered.  

Snippet 1.0

Now comes the hello world. Type the following command and press enter(ignore the $. The $ is the one which I will be appending in the beginning to show the command starts here).


$ echo Hello World
Hello World

Now lets look in detail about the echo command. The echo command is a command which echos(prints) a set of strings as its output.

The syntax is:

echo [options] [string1]

Options:
The options are some characters or commands which will modify the execution of the echo command from its default style.

String:
The string is the string that you want to print on the screen.

We will deal in detail about echo and its power in detail when we encounter the need of it.

Now what we all have to know is U/Li NUX has a terminal. In which you can enter command and get some job done. The echo is one of the commands which prints something as its output. It has some standard syntax and a standard format of output. It also has some options to change the way how it behaves.

The Terminal

Ok to learn Unix/Linux you should have access to something called the terminal which is like a note pad or like a command prompt in windows.... command prompt seems to be more appropriate....


In UBUNTU the Terminal is on accessories...
 

When you open the terminal you see something like this...

It will start from the home directory. Home directory is the default directory in which you are in I mean it is the directory from which Linux allows you to use. A directory is a collection of sub-directories and files. Technically in Linux a directory is also a file of type directory will deal with this later.

Now coming back to the terminal. Terminal is like a gate which allows you to interact with the hart of the OS the kernel. The kernel interacts with the hardware and the hardware, the terminal interacts with the kernel and you interact with the terminal.

Now this is the terminal. You can start interacting with it soon...

Unix What the hack is that...?

Hi again,
         I don't know much....but most UNIX geeks tells that the UNIX is one of the most Robust OS... OS is nothing but an operating system something like Windows and MAC. Ok... LINUX is like UNIX.... And mostly it behaves so. So I prefer you guys to have a LINUX OS and try the proceedings.... I prefer UBUNTU which is very user friendly and stays us being Human being rather than us having a geeky beard.

Ok where to get the UBUNTU thing....?

The UBUNTU is a linux based OS available freely (yeah its free!!!). You can download it from

http://www.ubuntu.com/download/ubuntu/download

The above link will lead you to the official UBUNTU web page where you can download the   whole ISO and write it in a CD/DVD and do the installation. If you don't feel like installing a whole new operating system just Try it in VM or UBUNTU itself provides a feature of installing it inside windows and you can try that too.

Ok installation and all you just take care of.....

Am a newbe?... are you..?

Hi gys,
          Am an armature, newbe for Unix/linux. But now I have started learning Unix so I am interested in recording my learning in a document. I had proffered blogging the whole thing because this may be useful to at least one guy who accidentally comes across the blog. Since this is my first technical blog I don't know how the standard but hope I will do good.