Linux/C2/Basics-of-System-Administration/English-timed

Time	Narration
00:02	Hello and welcome to the Spoken Tutorial on Basics of System Administration in Linux.
00:09	In this tutorial, we will learn the following.
00:13	* adduser
00:14	* su
00:16	* usermod
00:17	* userdel
00:18	* id
00:19	* du
00:20	* df
00:22	I am using Ubuntu 10.10 for this tutorial.
00:27	As a prerequisite please go through the spoken tutorial on General Purpose Utilities in Linux
00:35	which is available on this website.
00:39	One must have "admin" access in order to execute the commands shown.
00:47	Let us first learn how to create a new user.
00:53	The "adduser" command will create a new user login for us along with authentication.
01:01	We can add any user account with the help of “sudo” command.
01:06	Let me give you a brief explanation about the “sudo” command.
01:11	"Sudo" command allows the administrative user to execute a command as a super user.
01:19	The "sudo" command has many options. We will learn about the options as we go further in this tutorial.
01:27	Lets now learn how to create a “New User”.
01:32	Open the “Terminal” by pressing the keys “Ctrl, Alt and t” simultaneously on your keyboard.
01:45	I have already invoked the “Terminal” here.
01:49	Here, type the command “sudo space adduser” and press Enter.
01:58	You will be prompted for a password.
02:01	I will give the “Admin” password here and Enter.
02:07	The typed password on the terminal is not visible.
02:11	So we have to type the password carefully.
02:16	Once done, a message “adduser: Only one or two names allowed” is displayed.
02:27	So, let us create a new user account named “duck”.
02:34	Type the command:
02:36	sudo space adduser space duck and press Enter.
02:45	We have created a new user called “duck”.
02:49	In the process of creating a new user, a separate “home” directory for that user has also been created.
02:58	Please note that we will be prompted for a new password for the user “duck”.
03:05	Type the password of your choice. In my case, I am going to type “duck” as the password and press Enter.
03:17	Please type the new password again.
03:20	The password is asked twice for security reasons and for confirmation.
03:26	Now our password for the new user is updated.
03:31	We will be asked for other details too.
03:35	But for the time being, I will enter only the “Full Name” as “duck” and leave the rest of the details blank by pressing the Enter key.
03:46	Enter.
03:47	I will confirm this by entering “y”.
03:51	This is to confirm that all the information is correct.
03:55	Let us now check, if the user account has been created.
04:00	To do this, please type at the command prompt:
04:04	“ls space /(slash) home”
04:09	and press Enter.
04:11	To show the list of users in the home folder “ls” command is used.
04:17	And here is our newly created user named “duck”.
04:23	Let me switch back to the slides.
04:26	Now the next command is the “su”
04:30	“su” stands for “Switch User”.
04:34	This command is useful for switching from the current user to another user.
04:39	Let us go to the Terminal now.
04:43	Enter the command
04:45	“su space hyphen space duck” on the “Terminal”and press Enter.
04:53	You will be prompted for a password.
04:56	I shall type the user “duck's” password here please recall that it was “duck” itself.
05:04	Please notice that, the Terminal switches from the previous user to the new user, which is “duck” in our case.
05:14	To logout from this user, type
05:17	“logout” and hit Enter.
05:22	Now the terminal logs out from the current user “duck” and comes back to the previous user account, which is “vinhai” in our case.
05:31	Let us learn about the “usermod” command.
05:35	The “usermod” command
05:37	Enables a super user or root user to modify the settings of other user accounts such as
05:46	Change the password to no password or empty password.
05:50	Show the date on which the user account will be disabled.
05:55	Let us try this command and see.
05:57	Let me switch to the terminal now.
05:59	Let me show you how to set a date of expiry for the user account duck.
06:05	Here at the command prompt type
06:09	sudo space usermod space -(hyphen)e space 2012-(hyphen)12-(hyphen)27 space duck
06:33	and press Enter.
06:37	The user account expiry date is set as mentioned in the command here with the help of the option “-e”.
06:46	Now you have set an expiry date for the user account “duck”.
06:52	Let us now talk about the “uid” and “gid” commands.
06:57	“id – command” is used to check the identities of all the users and groups
07:04	To know about the identity of the user, we use “id space -(hyphen)u”.
07:12	To know about the identity of the group users, it is “id space -(hyphen)g”
07:20	Now lets work on this.
07:22	At the terminal, let us type
07:25	“id” and press Enter.
07:29	Now we can see the User IDs and Group IDs on the system that we are using
07:37	To get only the user id, we use “-(hyphen)u” option.
07:43	Let us type the command, “id space -(hyphen)u”
07:49	and press enter.
07:50	Now we can see only the ids of the users.
07:55	But what if we need to know the names of the users?
08:00	To find that out, we will type
08:02	“id space -(hyphen)n space -(hyphen)u” on the terminal hereand press Enter.
08:13	Now we can see the names of the users instead of their ids.
08:20	Let us now learn the commands for Group IDs.
08:24	Lets type “ id space -(hyphen)g”.
08:29	Here we can see the group ids.
08:32	If we want to view all the current user's group IDs, type
08:38	“id space -(hyphen) (capital)G” and press Enter.
08:46	Please notice that I have typed G in capital letter.
08:50	See the result for yourself.
08:53	Now let us learn how to delete a user account.
08:57	For this we use “userdel” command.
09:00	We can delete an user account permanently with the help of the “userdel” command.
09:07	Lets try this on the terminal.
09:09	Here type “sudo space userdel space -(hyphen)r space duck”.
09:22	I have used the -(hyphen)r option.
09:25	This is to remove the user along with his home directory.
09:30	Let us press Enter and see what happens.
09:34	Now the user “duck” has been deleted.
09:38	Check this by typing
09:41	“ls space /(slash)home” and press the Enter.
09:47	We will find that, the user account “duck” has been deleted.
09:53	Let me go back to the slides now.
09:56	Some of the useful commands in Linux System Administration are “df” and “du”
10:03	The “df” command gives a report on the free space available on the disk.
10:08	And the “du” command gives a report on how much space a file has occupied.
10:13	Please try these two commands and find the output for yourself as an assignment.
10:19	Let us shift to the terminal, I shall show you a fewuseful options used with the “df” command.
10:26	Please type df space -(hyphen)h and press Enter.
10:33	Here it shows the size of the Filesystem, and the space is used.
10:38	It also shows the space mounted on in a human readable format.
10:46	Let us now try some options with the “du” command
10:50	At this point i assume that you have created some text files in your home folder.
10:57	If not please refer to the tutorial on “General Purpose Utilities in Linux”.
11:04	I have already created some text files in my home directory to execute the commands.
11:11	Goto “home folder” on the terminal by typing
11:15	“cd space /(slash) home” and press Enter.
11:20	Then type du space -(hyphen)s space *. (astrix) dot txt and press enter.
11:33	This command will give you a report on the txt files available in the directory along with its file sizes.
11:43	As an assignment, at the command prompt type
11:47	“du space -(hyphen)ch space *.(astrix dot)txt” and see what happens.
11:59	Let me go back to the slides.
12:01	To summarise, we have learnt:
12:03	“adduser” command to create a new user.
12:06	“su” command to switch from one user to another user.
12:09	“usermod” command to change the user account settings.
12:12	“userdel” command to delete the user account.
12:15	id command to know the information about user ids and group ids.
12:20	“df” command to check the file system size and its availability.
12:24	“du” command to check the space occupied by a file.
12:27	This brings us to the end of this tutorial on “Basics of system administration”
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Contributors and Content Editors

Minal, PoojaMoolya, Pratik kamble, Sakinashaikh, Sandhya.np14, Vasudeva ahitanal