LOGGING IN AND LOGGING OUT FROM A LINUX SESSION.

Starting a Linux Session: Logging in

A user of a Linux based system works at a user terminal. After you connect to the Linux system, a message similar to the one shown below appears at the terminal.

Red Hat Linux release 6.0 (Hedwig)
Kernel 2.2.5 - 15 on an i586
login: _

Each user has an identification name called the user name or the login name, which has to be entered when the login: prompt appears. At the login: prompt, after you enter your login name, you are asked to enter your password.

Linux keeps track of all the user names and the information about users in special files (the shadow and passwd files under the /etc directory). When you enter the login name and password, these are checked in the above mentioned files.


If the login name entered does not match any of the user names in the file, the login message is displayed again. This ensures that only authorised users can access the machine. When a valid user name is entered at the terminal, the [user_name@localhostcurrent_directory_name] $ symbol is displayed on the screen.

This is the shell prompt, in which user_name is the user' s login name and current_directory_name is the user' s current working directory.

The administrator assigns each user a HOME directory when a new login account is created. When you log in, you are taken directly into your HOME directory. In Linux, login names (usernames) are usually the names of the users, and their HOME directory usually, although not necessarily, has the same time.

For instance, if your user name is tom and your HOME directory name is also tom, after logging in, you will see the following prompt on the screen.

[tom@localhost tom] $

You can now start working on Linux.

You have to be careful while typing your Login name and password, as this are case-sensitive. The entire login process appears like the one shown below:

Red Hat Linux release 6.0 (Hedwig)
Kernel 2.2.5 - 15 on an i586
Login:Tom
password: [user enters password here]
Last login: Sat Sep 18 12:18:02 from 172.17.55.167
[tom@localhost tom] $

A Sample Linux Login Screen