groups Archives • Linux Tips

Short: Show The Groups You Belong To

Today’s article, as was indicated in the title, is a short article where we learn how to show the groups you belong to. It’s just a simple command, so we’ll toss in some extra knowledge. But, this is just a short article. You won’t have much to do in this article.

The latest article explained groups and can be read by clicking this link:

List All The Groups In Linux

The last article explained how to list all the available groups in Linux. This one will explain all the groups your user account belongs to. If you want to know the groups you belong to, it’s simple enough.

If you didn’t read the article, Linux is a multi-user operating system. There are also groups. A user can belong to multiple groups and have permissions matching those groups. The example I gave in the previous article was the sudoers group. You (probably) belong to that group, giving you access to the sudo command. That is how you have elevated permissions for your account, which is quite different than using the root account.

Even if you don’t know this, you’re almost certainly a member of multiple groups. In the previous article, we learned how to show those groups and today we’ll learn how to show the groups you belong to.

Show The Groups You Belong To:

If you want to show the groups you belong to, you’ll need to have an open terminal. Just press CTRL + ALT + T and your default terminal should open. Otherwise, open a terminal from your application menu.

With your terminal open, you can show the groups you belong to with this command:

groups

groups

Your output will be different but here’s an example:

$ groups
kgiii adm cdrom sudo dip plugdev lpadmin sambashare vboxusers

1 2	$ groups kgiii adm cdrom sudo dip plugdev lpadmin sambashare vboxusers

This also works with other users. Here’s the syntax:

groups <user_name>

1	groups <user_name>

That will show the groups that the user belongs to. It’s a pretty simple thing to learn and a pretty handy thing to learn. It’s so simple and easy that this is an intentionally short article.

Closure:

There you have it… It’s a short article but showing the groups you belong to isn’t a complicated affair. This is something anyone can do and there’s no reason to make the article longer than it already is. While I could make it longer, it’d be wasting my time and your time. It’s just that easy.

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List All The Groups In Linux

This is going to be a simple enough article where we list all the groups in Linux – specifically your Linux. (Your list of groups may not be the same as my list of groups, of course.) This isn’t complicated but might be important to some of you, so we might as well write about it.

I’ve often mentioned that Linux is a true multi-user operating system. That is, you have many users, each with assigned tasks and permissions. You have users for everything from root to printing.

Well, along those same lines, Linux also uses groups. You can not only set permissions on a per-user basis, you can set permissions on a per-group basis. Any member belonging to that group will have the same permissions as that group.

A good example is ‘sudo‘. That’s a group you likely belong to. Because you belong to the sudo group you have access to the sudo command. This lets you have elevated permissions to perform various operations on your system. Make sense?

We’ll be using a new tool for this…

getent:

The getent command is used to read various databases. This is fine because ‘groups’ is one of the databases that getent can read. You won’t need to install anything to run this command.

You can check the man page with this command:

man getent

1	man getent

From there, you’ll see that getent is described like so:

getent – get entries from Name Service Switch libraries

So, it’s a database reading tool more than anything else.

If you’d like an easier way, we’ll do the same with the cat command.

cat:

I really shouldn’t have to describe the cat command. We’ve used it plenty of times. It takes the contents of a file and spits them out to your terminal (standard output). It’s an oft-used tool in the Linux world. Once again, you won’t have to install anything.

You can check the man page with this command:

man cat

man cat

At that point, you’ll see that the cat command is described like this:

cat – concatenate files and print on the standard output

See? It’s the correct tool for the job. We want to take the contents of a file and read it in the terminal. The cat command is perfect for that.

I’ll show you how to list all the groups in Linux with both commands. You can pick your favorite and just use that command. Either command will work just fine for this job.

List All The Groups In Linux:

If it wasn’t obvious from the above, this is yet another task for the terminal. If you don’t have an open terminal, you can probably open one by pressing CTRL + ALT + T. If that doesn’t work, find the terminal in your application menu and click it.

With your terminal open, run the following command:

getent group

1	getent group

While not of much use, here’s an example output:

$ getent group
root:x:0:
daemon:x:1:
bin:x:2:
sys:x:3:
adm:x:4:syslog,kgiii
tty:x:5:
disk:x:6:
lp:x:7:
mail:x:8:
news:x:9:
uucp:x:10:
man:x:12:
proxy:x:13:
kmem:x:15:
dialout:x:20:
fax:x:21:
voice:x:22:
cdrom:x:24:kgiii
floppy:x:25:
tape:x:26:
sudo:x:27:kgiii
audio:x:29:pulse
dip:x:30:kgiii
www-data:x:33:
backup:x:34:
operator:x:37:
list:x:38:
irc:x:39:
src:x:40:
gnats:x:41:
shadow:x:42:
utmp:x:43:
video:x:44:
sasl:x:45:
plugdev:x:46:kgiii
staff:x:50:
games:x:60:
users:x:100:
nogroup:x:65534:
systemd-journal:x:101:
systemd-network:x:102:
systemd-resolve:x:103:
crontab:x:104:
messagebus:x:105:
systemd-timesync:x:106:
input:x:107:
sgx:x:108:
kvm:x:109:
render:x:110:
syslog:x:111:
tss:x:112:
rtkit:x:113:
systemd-coredump:x:114:
lpadmin:x:115:kgiii
bluetooth:x:116:
ssl-cert:x:117:
netdev:x:118:
uuidd:x:119:
lightdm:x:120:
nopasswdlogin:x:121:
tcpdump:x:122:
_ssh:x:123:
plocate:x:124:
avahi-autoipd:x:125:
nm-openvpn:x:126:
geoclue:x:127:
pulse:x:128:
pulse-access:x:129:
scanner:x:130:saned
_flatpak:x:131:
avahi:x:132:
saned:x:133:
colord:x:134:
fwupd-refresh:x:135:
kgiii:x:1000:
sambashare:x:136:kgiii
sssd:x:137:
vboxusers:x:138:kgiii
vnstat:x:139:

$ getent group

root:x:0:

daemon:x:1:

bin:x:2:

sys:x:3:

adm:x:4:syslog,kgiii

tty:x:5:

disk:x:6:

lp:x:7:

mail:x:8:

news:x:9:

uucp:x:10:

man:x:12:

proxy:x:13:

kmem:x:15:

dialout:x:20:

fax:x:21:

voice:x:22:

cdrom:x:24:kgiii

floppy:x:25:

tape:x:26:

sudo:x:27:kgiii

audio:x:29:pulse

dip:x:30:kgiii

www-data:x:33:

backup:x:34:

operator:x:37:

list:x:38:

irc:x:39:

src:x:40:

gnats:x:41:

shadow:x:42:

utmp:x:43:

video:x:44:

sasl:x:45:

plugdev:x:46:kgiii

staff:x:50:

games:x:60:

users:x:100:

nogroup:x:65534:

systemd-journal:x:101:

systemd-network:x:102:

systemd-resolve:x:103:

crontab:x:104:

messagebus:x:105:

systemd-timesync:x:106:

input:x:107:

sgx:x:108:

kvm:x:109:

render:x:110:

syslog:x:111:

tss:x:112:

rtkit:x:113:

systemd-coredump:x:114:

lpadmin:x:115:kgiii

bluetooth:x:116:

ssl-cert:x:117:

netdev:x:118:

uuidd:x:119:

lightdm:x:120:

nopasswdlogin:x:121:

tcpdump:x:122:

_ssh:x:123:

plocate:x:124:

avahi-autoipd:x:125:

nm-openvpn:x:126:

geoclue:x:127:

pulse:x:128:

pulse-access:x:129:

scanner:x:130:saned

_flatpak:x:131:

avahi:x:132:

saned:x:133:

colord:x:134:

fwupd-refresh:x:135:

kgiii:x:1000:

sambashare:x:136:kgiii

sssd:x:137:

vboxusers:x:138:kgiii

vnstat:x:139:

You can get the same output with the cat command. That might be easier to remember for newer users. After all, you should be familiar with the cat command. That command is simple enough.

cat /etc/group

1	cat /etc/group

That will give you the same results as the ‘getent’ command above. Obviously, the group name is the first column.

I’m not sure where I learned this, but you can just list the first field and get a list of groups without any additional information. Just use this command:

cut -d: -f1 /etc/group

1	cut -d: -f1 /etc/group

That’s not nearly as useful as it could be, but I figured I’d share.

Closure:

Well, if you wanted to list all the groups in Linux, you now know how to do so. If you didn’t know about groups, you now know that you have groups and how to list them. So, you might as well add that to your notes and keep it in mind. (The groups subject may appear in a future article!)

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:

sudo usermod -a -G <group_name> <user_name>

1	sudo usermod -a -G <group_name> <user_name>

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:

grep <user_name> /etc/group

1	grep <user_name> /etc/group

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.

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.