Category: OS

Below is the video showing how to install ns2 ,network stimulator on Ubuntu :

Shell Scripting:While login to UNIX

In UNIX,shell is a very strong and most important tool.
When you login to UNIX , a shell executes and you see a login prompt, this shell can be a bourne shell , a POSIX shell, etc (depending on the versions of UNIX) i.e. for LINUX it is a bourne shell.
When a user types a username , a password prompty comes and when user types a password ,the entry is matched with the preentry made in file /etc/passwd .
Now if the entry matches the user successfully get loged in but if the password doesnt match the GETTY program takes over and we get a new login prompt untill you made a true entry.

Thats all for the unix shell scripts used while the user makes a login.For more such informations give a like to our facebook page and leave your valuable comments too.

Port numbers and their ranges

The port numbers are basically divided into three ranges: the Well Known Ports,the Registered Ports, and the Dynamic
or Private Ports.

From 0 to 1023 are the well known ports.

From 1024 to 49151 are the registered ports.

from 49152 to 65535 are the dynamic or private ports.

Bash (Unix Shell)

There are many tools in linux for command executions and one of them is called the “shell programming”.

The most common Linux shell is named “Bash” is the default shell on linux. The name comes from “Bourne Again SHell” ,written by Brian Fox.

As it is the default shell of linux so people prefer using it than any other shells as it makes them to use it worldwide as it now becomes machine independent and operating system independent.

There are two ways to use the shell: interactively and by writing shell scripts( known as shell scripting ).

* In the interactive mode, the user types a single command or a short string of commands and the result is printed out on the screen.

*In shell scripting, the user types anything from a few commands  to an entire program( collection of programs) into a text editor, then executes the resulting text file as a shell script.

How to open telnet port in windows 7

In windows xp and lower versions telnet port i.e. 23 is open by default but there comes a need to open it manually in case of windows 7.

Following are the simple steps to do that:

1.Go to control panel

2.programs>programs and features>Turn windows features on or off

3.There just check the Telnet Client  button and thats all.

4.Restart the system.

NOTE: telnet is used for remote login so i advise to keep it open only if you are using it , not just for fun,it can be a wrong decision and you can be very close to be hacked!!!!


How to install ubuntu linux….READ MORE

bash shell……READ MORE


My friend asked me today about the problem he his facing in ubuntu linux ,that he was unable to switch from the cli mode to the gui mode for that there is simple command that is:


enter it through root and you will be able to switch from cli mode to graphics mode.

Other than that there are more commands too:

init 5

This is default for graphical mode and by entering it can be switched from cli to gui.

How to install Ubuntu linux

while browsiing today i got a very nice video on how to install ubuntu  linux.So sharing it might be useful for you: