How To: Add A User To A Group

Today’s article is going to teach you how to add a user to a group. It’s not particularly difficult, but it’s something everyone should know. If you don’t know how to add a user to a group, this article is meant for you.

This article is going to make a few assumptions. The first is that you’re familiar with cat /etc/passwd which will tell you what groups a user belongs to. It also assumes that you’re familiar with cat /etc/group – where you can find supplementary information.

Furthermore, you should also be aware of the groups command, which is a handy command, probably worthy of its own article, that lets you know what groups you already belong to. So, there’s a bit you’re expected to know already, or at least be familiar with conceptually, but trust me when I say this is a very simple article and very straightforward.

Anyhow, if you’ve looked at those previous commands, you’ll see there are a lot of groups. Your user may or may not be a member of those groups, as the groups command will let you know. For myriad reasons, you may wish to add yourself or another user to different groups. Well, that’s what this article is actually about. It’s about showing you how to …

Add A User To A Group:

This article requires an open terminal, like many other articles on this site. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T and your default terminal should open.

The command we’ll be using for this exercise is ‘usermod‘. You can get a head start by using ‘man usermod‘ but we really won’t be needing most of that information. In reality, we only care about a couple of the flags. Still, usermod is a pretty expansive command, with many options. Still, it defines itself simply as:

usermod – modify a user account

See? Pretty straightforward still. The command we actually want is:

The -a means append (add) the user. The -G means groups – so the -a -G means add a user to a group. You can verify the command worked (though, well, you really don’t need to – ’cause, assuming  you did it properly it’ll work) with the following:

See? That’s it. You’ve learned how to add a user to a group – in under 500 words!

Closure:

Yup, it’s a nice and easy article for a skill you may need as you work with advanced group permissions. If you want to refine the permissions in your system, the sky’s the limit and it’s easy enough to add a user to a group if you need to. So, there’s another tool in your toolbox.

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Find Your Username In Linux

Today’s article is going to be fairly brief and easy, as it just covers how to find your username in Linux. For this exercise, we’ll be using a terminal and some basic commands. It shouldn’t be too stressful or difficult. In fact, it should be just the opposite.

When you open your terminal, you’re usually greeted with some information. In that information is typically your username. However, it’s possibly that this is no longer true. You could have it display anything you wanted, plus there’s a chance you’re logged in remotely and just can’t remember which terminal window is connected to which device.

So, there are some reasons why these commands exist. I mean, you should probably know your username. That’s not the kind of thing I forget, but I am getting older. Still, the commands exist and must exist for a reason.

My motto is that they wouldn’t have provided a path if they didn’t want you to get to the destination. (That’s not really my motto.) So, if there’s a command that’ll help you find your username in Linux, you might as well know it and know how to use it.

Find Your Username In Linux:

This article requires an open terminal, like many other articles on this site. If you don’t know how to open the terminal, you can do so with your keyboard – just press CTRL + ALT + T and your default terminal should open.

With that terminal open, let’s try echoing the $USER variable. It’s nice and easy, and it looks like this:

You can also use who and whoami as commands:

And:

There’s also w, which shows logged in users – so you may be able to deduce your username from that list. It just looks like a:

The ‘w’ command nice and handy, and has a bit more information about the user. It would look similar to this:

w command's output showing username
See? It’s pretty easy to see that there’s a user logged in – and more!

As you can see, there are a number of ways. I’m sure that I’m missing some. Feel free to chime in and add to the list. Basically, if you want to share it with the world, leave a comment. Otherwise, many readers know where to find me.

Closure:

And now you have another article. This one isn’t fancy, nor is it something you’re going to need all the time. However, it’s still a very basic and useful tool to add to your Linux toolbox. Things like these are the fundamentals. How to find your username in Linux is an absolute beginner move and a move that leads you forward to more knowledge.

Thanks for reading! If you want to help, or if the site has helped you, you can donate, register to help, write an article, or buy inexpensive hosting to start your own site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

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How To: Create a New User Without a /home Directory

There are legit reasons to create a new user without a /home directory. Maybe you want a new user to have limited access to just a few things, or a dedicated user that runs a single application. This article will show you how.

See, I was reading a forum post on Linux.org about a member that had set up a bunch of Linux computers for some learning children. One of the things that came up was that the kids were already trying to guess the password so that they could install games. 

That got me thinking about some security implications. What if they guessed the password and wanted to hide it? What if they used that password to create a new user, but one without a /home directory so that it wouldn’t be easily spotted by just using a file manager? It wouldn’t be impossible to find, but it’d not stand out immediately with a quick inspection. Besides, the new account’s password would remain the same even if the admin changed the password to the root account.

Well, if they get that advanced and guess that password, I kinda hope they read this article! Why? Because the world needs a little chaos and creativity! So, my fellow Linux.org forum user, this article is for you! Well, no… It’s for when the kids use a search engine to learn how to make a user account a little less obvious! 

Create a New User Without /home:

This one will be short and easy, perfect for budding Linux users! There are two easy ways to create a user without automatically making a /home folder. 

Both ways are done in the terminal, so you need to open it. To open the default terminal, use your keyboard and press CTRL + ALT + T.

Now, the first method is:

The second method is:

Those commands will both make a new user without a /home directory of their own. (Be sure to check ‘man useradd’ for more awesome things you can do.)

There are a couple more steps you can take, if you want. First, there’s no password assigned to the user you just created. So, let’s assign a password to them.

Follow the prompts to type in the password twice and you’re done with that step.

Next, the newly created user isn’t a member of sudoers – meaning it has no administrative rights. That’s easily fixed with the following command:

That command will make the new user a member of the sudoers group. Meaning they have administrative rights over the system. They can install software, remove software, delete files, create files, or even update the entire system.

The admin can still discover the new user by listing the users or poking around in the logs. However, the user won’t stand out immediately. There won’t be any new user folder in /home, so one may not have any reason to look. Additionally, changing the root password won’t matter. You’ll have to do something about the user they created.

And that, kids, is how you get started hiding stuff after you’ve discovered the root password! Use that account for your nefarious activities! You’re welcome!

Closure:

Nah, there are legit reasons why you’d want a user without a home folder. You may want that user to only access a limited set of applications or whatever. A keen admin would likely notice this fairly rapidly, so it’s not a great long-term strategy for hiding your game installing.

Thanks for reading! If you want to help, or if the site has helped you, you can donate, register to help, write an article, or buy inexpensive hosting to start your own site. If you scroll down, you can sign up for the newsletter, vote for the article, and comment.

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