Linux-for-Sys-Ads/C2/Modifying-User-Account/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:01 | Hello and welcome to the spoken tutorial on Modifying User Account in Linux. |
| 00:08 | In this tutorial we will learn about usermod command |
| 00:13 | Modifying attributes of user account |
| 00:17 | Locking and unlocking password or account |
| 00:21 | We will do this through some examples. |
| 00:25 | To record this tutorial, I am using Ubuntu Linux 16.04 Operating System |
| 00:33 | To practice this tutorial, you should have gone through the Linux System Administration tutorials on this website and |
| 00:42 | You must have root access to your computer. |
| 00:47 | The command usermod is used to modify the attributes of an already created user account. |
| 00:55 | This is the syntax. |
| 00:58 | Here the options part is not mandatory. |
| 01:03 | This command supports many options. |
| 01:06 | We will learn them through some examples. |
| 01:10 | Earlier in the series, we had created a user radha. |
| 01:15 | Now let’s modify the user account attributes of radha by using the usermod command. |
| 01:23 | Open the terminal by pressing Ctrl, Alt and T keys simultaneously on the keyboard. |
| 01:32 | First, we will login as superuser or root user. |
| 01:37 | To do so, type sudo space su and press Enter. |
| 01:44 | Type your password and then press Enter. |
| 01:48 | Notice, our login prompt has now changed to a hash symbol. |
| 01:54 | This indicates that we are in the root user mode. |
| 01:59 | Here onwards, please remember to press the Enter key after typing each command. |
| 02:05 | We will check the user id and group information for user radha. |
| 02:11 | On the terminal type id space radha |
| 02:17 | Notice, user ID of radha is 1002 |
| 02:23 | In order to modify user ID to 1100, |
| 02:28 | On the terminal we have to type- usermod space hyphen u in small letter space 1100 space radha |
| 02:40 | Now once again, type id space radha. |
| 02:45 | Notice that the UID has been changed to 1100. |
| 02:51 | usermod command can be used to modify a user’s primary and supplementary group. |
| 02:58 | User radha belongs to primary group CSE
And supplementary groups music_club and sports_club. |
| 03:08 | We will change the primary group from CSE to electronics. |
| 03:14 | We will also change the supplementary group to literature_club. |
| 03:20 | But we have not created the groups electronics or literature_club. |
| 03:27 | So, first we have to create these two groups. |
| 03:31 | Switch to the terminal.
Type addgroup space electronics |
| 03:39 | Group electronics is added with GID 1006. |
| 03:45 | Next, type addgroup space literature_club. |
| 03:51 | Group literature_club is added with GID 1007. |
| 03:58 | Now, to modify the primary and supplementary groups, type:
usermod space -g space electronics space -G in caps space literature_club space radha |
| 04:18 | hyphen capital G option removes the user from previous supplementary groups |
| 04:25 | In this case, it removes from the previous supplementary groups. |
| 04:29 | And adds the user to the new group literature_club |
| 04:35 | Type id space radha |
| 04:39 | Now we can see that the primary group is set to electronics.
And supplementary group is set to literature_club. |
| 04:49 | How can you add a user to a new supplementary group while retaining the previous groups? |
| 04:56 | For this, you should use -a option. |
| 05:01 | a option denotes append. |
| 05:05 | Say for example, user radha wishes to be in both music_club and literature_club groups. |
| 05:15 | For this type: usermod space hyphen a space hyphen G in caps space music_club space radha |
| 05:29 | Once again, type id space radha |
| 05:34 | Notice that user radha now belongs to two supplementary groups -
music_club and literature_club |
| 05:44 | Suppose we now want to change the login name itself from radha to testmod. |
| 05:52 | To do this, on the terminal type the following: usermod space hyphen l space testmod space radha |
| 06:04 | Now user radha has become user testmod. |
| 06:09 | Let’s search for testmod’s details in /etc/passwd file. |
| 06:17 | Type grep space testmod space /etc/passwd |
| 06:26 | Notice that the login name or user name has changed but the home directory remains the same. |
| 06:34 | Ideally, we should rename the home directory to match the login name. |
| 06:40 | There are 2 methods to do this. |
| 06:43 | Method 1:
We can manually rename the home directory to match the login name. |
| 06:50 | Let me do that now. |
| 06:52 | Type mv space slash home slash radha space slash home slash testmod |
| 07:02 | This command will rename directory radha to testmod. |
| 07:09 | Now, use any text editor to update the entry in slash etc slash passwd file. |
| 07:18 | I will be using gedit text editor. |
| 07:22 | Type gedit space slash etc slash passwd space ampersand |
| 07:32 | Now search for slash home slash radha |
| 07:37 | Replace it with slash home slash testmod |
| 07:42 | Save and close the file. |
| 07:45 | Press Ctrl C to stop the currently running process. |
| 07:51 | Now press the Up arrow key to get the grep command for user testmod.
And press Enter. |
| 08:00 | Notice that we have testmod as the new home directory for the user testmod. |
| 08:08 | Method 2: We can change the home directory for the user radha with the help of usermod command. |
| 08:17 | The syntax to change the home directory of user radha to the directory named testmod is as follows:
usermod space -m space -d space slash home slash testmod space radha |
| 08:37 | This command will change the home directory of user radha to testmod |
| 08:44 | -d is used to modify the directory for any existing user account |
| 08:51 | -m moves the contents of the existing home directory to the new home directory. |
| 08:59 | The new directory will be created, if it does not already exist. |
| 09:05 | Important note: We should write hyphen d option immediately after the new directory name.
Else we will get an error. |
| 09:17 | I will not demonstrate this because we have already changed the home directory using method 1. |
| 09:25 | Now let’s learn how to modify the user’s login shell and comments field. |
| 09:32 | Notice that our current login shell is /bin/bash and we have “Radha” as comments. |
| 09:41 | On the terminal type
usermod space hyphen s space slash bin slash sh space hyphen c space within double quotes This is modified user space testmod |
| 10:00 | Press the Up arrow key to get previous grep command. |
| 10:05 | Notice, we have changed the values in shell and comments field. |
| 10:11 | As a system admin you may need to lock a user account for various reasons, like violation of some rules by the user. |
| 10:21 | To lock the user testmod, type: usermod space hyphen L in Caps space testmod |
| 10:31 | Now type cat space slash etc slash shadow |
| 10:38 | On doing so, we get an exclamation mark added before the encrypted password for user testmod. |
| 10:46 | So, no password will match it anymore. |
| 10:50 | We have also seen this while locking password with passwd command. |
| 10:56 | It will lock only the access to password. |
| 11:00 | If you wish to lock the account itself, you should also set the expiry date to 1. |
| 11:07 | For that type usermod space hyphen capital L space hyphen e space 1 space username |
| 11:19 | It will prevent the user from logging in from any other source including ssh. |
| 11:26 | I will skip the demonstration of this command. |
| 11:30 | To unlock the account we have to type: usermod space hyphen U in caps space testmod |
| 11:41 | Once again check the contents of /etc/shadow file. |
| 11:47 | Notice, the exclamation mark is removed now. |
| 11:51 | It means the password is not locked. |
| 11:55 | We have seen all the options supported by usermod command. |
| 12:00 | You can use the man command anytime to get details of usermod command. |
| 12:06 | Type man space usermod |
| 12:10 | Notice, all the details about this command as shown. |
| 12:16 | Type q to quit from this command. |
| 12:20 | To exit from the root user access, type exit
And press Enter. |
| 12:27 | This brings us to the end of this tutorial.
Let us summarize. |
| 12:33 | In this tutorial we learnt about-
usermod command, Modifying attributes of user account, Locking and unlocking password or account |
| 12:47 | As assignment, modify user account amit such that
Primary group is electronics |
| 12:56 | Supplementary groups are music_club and literature_club |
| 13:03 | Set home directory as amit_newDir |
| 13:09 | Include comment "Stream Change Student" |
| 13:13 | Perform all the mentioned tasks in a single command. |
| 13:18 | Check the entry of user account amit in /etc/passwd and /etc/group files |
| 13:29 | The video available at the following link summarises the Spoken Tutorial project.
Please download and watch it. |
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| 13:54 | Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India. |
| 14:00 | The script has been contributed by Antara And this is Praveen from IIT Bombay signing off.
Thanks for joining. |
