|00:01||Hello and welcome to the spoken tutorial on Creating User Account in Linux.|
|00:08||In this tutorial we will learn about|
|00:10||Creating user account with different options
slash etc slash passwd file, slash etc slash shadow file
|00:22||To record this tutorial, I am using Ubuntu Linux 16.04 OS|
|00:29||To practice this tutorial, You should have gone through the Linux tutorial series on this website.|
|00:36||And you must have root access to the computer.|
|00:41|| In an earlier tutorial on basics of system administration, we have learnt
To add a user using the following command:
|00:49||Please note that the option field here, is not mandatory.|
|00:54||We will elaborate on the option field in this tutorial.|
|00:59||Open the Terminal by pressing Ctrl, Alt and T keys simultaneously on the keyboard.|
|01:06||First, you should login as superuser or root user.|
|01:11||To do so type: sudo space su and press Enter.|
|01:18||Type your password and then press Enter.|
|01:22||Notice, our login prompt has changed to a hash symbol.|
|01:27||This indicates that we are in the root user mode.|
|01:31||Now, let’s consider a scenario of a college.|
|01:35||We will have students, departments, etc.|
|01:39||As a system administrator, you should first create a user account for individual students.|
|01:46||Let’s add one user say amit using adduser command.|
|01:51||So, on the terminal type: adduser space amit and press Enter|
|02:00||It will prompt us to type the password for the user amit.|
|02:04||Let’s type pass underscore amit and press Enter.|
|02:10||Retype the same password and press Enter.|
|02:14|| When it prompts for the Full Name field, type the name of the user as Amit with A in caps.
|02:23||Leave the other fields empty by pressing the Enter key.|
|02:28|| Press Y to confirm that the information you provided is correct.
|02:36|| So, we got back our root command prompt.
The user amit is created now.
|02:42||Linux automatically assigns a UID or User ID to the user.|
|02:49|| It also creates a home directory for the user in the system’s home folder.
In this case, it is slash home slash amit
|03:00||A group is also created with the same name as the username of the user.|
|03:05||Now, say we want a customized user ID or group|
|03:11||Or a home directory other than the default one|
|03:15||Or we want to change the default login shell|
|03:20||adduser supports options for each of these requirements.|
|03:25||Also you can combine multiple options to set multiple values in a single command.|
|03:32||Hyphen u option is used to set user ID|
|03:37||Hyphen home sets user home directory|
|03:41||Hyphen shell sets the login shell for the user|
|03:46||Hyphen c option is used to mention comments|
|03:51||Let us take an example.|
|03:53||Say we want to add a user Kaushik with
user ID as 1050
|04:00||home directory as testdir|
|04:04||login shell as slash bin slash sh|
|04:08||Also add “Kaushik is a re-registered student” in the comments.|
|04:14|| Switch to the terminal.
Let me clear the terminal.
|04:18||Type the command as shown here|
|04:26||It will ask you to enter the password for Kaushik.|
|04:30||I will type the password as pass underscore kaushik
|04:37||Retype the same password and press Enter.|
|04:42|| Give the Full Name of the user as Kaushik with K in caps
|04:51||And proceed as we have done before.|
|04:57||So, the user kaushik is created now.|
|05:01||Now type ls space /home and press Enter.|
|05:07||Notice, we have a new directory testdir.|
|05:12||How can we view other information such as user ID, login shell etc.?|
|05:19||In Linux, all configuration files are stored in simple text files.|
|05:25||/etc/passwd file contains the entire information about all the user accounts.|
|05:33||Let us have a look at the /etc/passwd file.|
|05:37||Switch to the terminal|
|05:40||Type cat space /etc/passwd and press Enter.|
|05:48||There will be an entry in this file for every user on the system.|
|05:53||Our passwd file shows this line for user Amit.|
|05:58||Each line has seven fields separated by colon.|
|06:02||Let us understand the fields one by one.|
|06:06||The first field is the username amit.|
|06:10||Remember, username should start with a lowercase letter, followed by any number of lowercase letters or digits|
|06:19||No special character other than underscore is allowed in the username|
|06:25||You should remember this while you are creating a user account|
|06:29||The second field is for password.|
|06:32||An x character indicates that the encrypted hash password is stored in the file /etc/shadow.|
|06:41||The third field is user ID for that particular user.|
|06:46||User id 0 is reserved for root user.|
|06:50||User ids upto 999 are reserved for other administrative or system users.|
|06:58||Real user account id starts from 1000.|
|07:02||So, you should specify a number more than 1000 in the adduser command.|
|07:08||The fourth field stores the primary group id for the user.|
|07:13||At the fifth place, we have the comments field.|
|07:17||It basically stores information about the user such as name of the user, room number, phone number, etc.|
|07:26||The sixth field indicates the home directory for the user.|
|07:31||At the end, we have the login shell of the user.|
|07:36||Notice that, we have default values set for user Amit.|
|07:42||However, user kaushik is created with our customized values.|
|07:48||Now, let’s have a look at the /etc/shadow file, where the encrypted passwords are stored.|
|07:57||Type cat space /etc/shadow and press Enter.|
|08:05||In this file, every line has information about a particular user.|
|08:10||And each line contains various fields separated by colon.|
|08:16||The first field is username, which must correspond to username field in /etc/passwd file.|
|08:25|| Notice, the second field is the encrypted password for that user.
Let us skip the other fields for now.
|08:33||To exit from the root user access, type exit and press Enter.|
|08:39|| This brings us to the end of this tutorial.
Let us summarize.
|08:44|| In this tutorial we learnt about- Creating user account with different options like
Specific user id, Specific Home Directory, Specific shell
|08:56||And adding comments|
|08:59||We also learnt about some of the fields in the */etc/passwd and /etc/shadow files.|
|09:10|| As an assignment
Create user ankit with User ID as 1500
|09:17||Home directory named ankit underscore newdir|
|09:22||Login shell as /bin/csh|
|09:27||Include “Hostel 15” in the comment|
|09:30||Use a single command to perform all the tasks|
|09:34||Check the /etc/passwd file for the details of user account ankit|
|09:41|| The video at the following link summarises the Spoken Tutorial project.
Please download and watch it.
|09:49|| The Spoken Tutorial Project team conducts workshops and gives certificates.
For more details, please write to us.
|09:58|| Do you have questions in this Spoken Tutorial?
Please visit this site.
|10:03||Choose the minute and second where you have the question.
Explain your question briefly.
|10:10||Someone from our team will answer them.|
|10:14||The Spoken Tutorial forum is for specific questions on this tutorial.|
|10:19||Please do not post unrelated and general questions on them.
This will help reduce the clutter.
|10:26||With less clutter, we can use these discussion as instructional material.|
|10:32||Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.|
|10:38|| The script has been contributed by Antara and this is Praveen from IIT Bombay signing off.
Thank you for joining.