Lesson 1-Logging On to the System

Overview

Importance of UNIX/Linux.

Logging on to the system.

Importance of UNIX/Linux

Most Internet servers and all the fundamental computing

structures run on UNIX/Linux systems.

Most communication networks run on UNIX/Linux systems.

The general infrastructure for communications, programs,

smart devices, and critical data is managed on UNIX/Linux

systems.

Importance of UNIX/Linux

Records, research, communication, development, and

publications depend on applications provided by UNIX/Linux

systems.

File serving for desktops, e-mail, and an enormous portion

of publishing run in UNIX/Linux environments.

Logging On to the System

The UNIX system’s ability to serve multiple users at a time

is one of its primary features.

A unique account associated with a login name is created

when an administrator adds a new user to a system.

Entry to the UNIX system is granted only if the user

provides a login name and a password that match an

established user on the system.

A user having a ‘root’ login is granted the extensive powers

needed to administer the system.

Logging On to the System

Logging On to the System

Character Window Log On Screen

Logging On to the System

Terminal Window Log on Screen

Logging On to the System

Ensure that the username and password is entered using

the correct character-case, since UNIX/Linux is case-

sensitive.

In most systems, the login name and the password are in

lowercase letters.

Passwords are not displayed on the screen.

Care should be taken to avoid typing mistakes.

Confusion between similar looking characters should also

be avoided. For example, the alphabet O and the number

zero (0).

Logging On to the System

Logging On to the System

Terminal Window interaction

Graphical Window interaction

Terminal Window Interaction

Terminal Window Screen

Terminal Window Interaction

The “date” command is used to display the current date

and time.

The “exit” command is used to log off from the terminal

environment.

Graphical Window Interaction

Graphical Window Screen

Graphical Window Interaction

Logoff in Graphical Window Interface

Summary

A valid username and a password are required to access a

UNIX/Linux system.

The root user has the extensive powers needed to

administer a UNIX/Linux system.

A user can log in from the terminal Window or the graphical

Window.