Linux User Administrtion

OBJECTIVES       

1. Crating a user account and assigning it to a perticular group.

2. Changing theexpirtion dateofa particular user or group.

3. Deleating a particual group or a user account.

CONCEPTS  

System administration or sysadmin defines the rolesand responsibilities of an individual

                   Who maintain and operate a computer system.  System admiistrator is the main ser of the Linux that handles the different tasks ;in the system.  Such as the hardware devices installations.  Configuring application software ( open Office backing up and restoring files, insatlling software package management as well as managing memeory and aanging process.  Linux operating system is a multiuser.  Multitasking operating system .  multiuser features emnables many people to have their accounts on linux system and work with the Linux operting systm.  You can assign each person his with his own login account.  Similary, multitasking feature enables you to schedule and execute multiple tasks (program) sinultaneously.  You can creae user andgroups in Linux using the user addcommand for creating user and. Add group for adding group in Linux and can also modify,  anddelete user accounts and group.

As an admisnistrator, you need to handle two most important responsibilitities that are to look agterthe administration and monitoring the users on a Linux network.  There are some basic command line tools that you have to know in order to create, monitor, and delete user accounts on a Linux network.

Basic Command Line Tools

In this section,  we explain how to create, modify, delete, and disable user accounts using command line tools in Unix environment.

Creating a User

Creating  a new user account is quite easy. For this , you just need to run the useradd command from the commandline. For example to create a user called Mahedra,  you can run useradd command as follows :

#useradd Mahedra

This adds a new entry in /etc/passwd file.  By default, this file store all user account related information.

Ther is no default pasword for  the previously created user Mahedra.  In order to create a password for this user, You jus need to type the passwd command on the command line as follows:

#passwd Mahedra

This will prompt you to enter a password.  Enter the password and pres enter.  You will be asked to confirm the password.  Type the password again and press enter. As long as you typed the same password in both times.  You have finished adding a new user.  If you did not enter the same password both times, yu will be asked to reenter the password again until you confirm it correctly.

CASE:1 let’s take an example where you have a group of users from an IT department .  they regularly use a spreadsheet apllication on a sysytem.  You could create a new group called finace and make it the default group for spreadsheets.  To crate group, run the following groupadd command:

#groupadd finance

 Now, if you need to crate a spradsheet user named mahendra, you could use the following command:

#useradd Mahendra –g finance

 This command crates a user named mahendra with a default group of finance.

If existing users need to be placed in the IT group, you could run the following command:

Chgrp even IT 

It would make the IT group deven’s new deafult group.  If you ned to make a particular user member o more than one group at a time, use the  -G opting with the useradd command : 

Useradd mahendra –G IT, finance 

The proceding comand creates the user mahedra with a deafult group of Mahendra.  At the same time , this user also becomes a member of the groups IT and finance.  To see the existing groups and the members, run the following command: 

#cat/etc/group 

The etc/group file have four segments (group name:password:group ID:users) that are separated by colons.  By seeing this file you can find the groups to whom Mahedra belong.