Linux user group listing

Linux Show The Groups a User Is In

Example

pen a command-line terminal (select Applications > Accessories > Terminal), and then type:
$ groups
Sample outputs:

You are part of all of the above groups. To find group memebership for root user, enter:
$ groups root
Sample outputs:

Please note that (from the groups man page):

Primary and supplementary groups for a process are normally inherited from its parent and are usually unchanged since login. This means that if you change the group database after logging in, groups will not reflect your changes within your existing login session. Running `groups’ with a list of users causes the user and group database to be consulted afresh, and so will give a different result.

You can also use the id command as follows to get the same information:
$ id -Gn
$ id -Gn userName
$ id -Gn vivek

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How Do I Find Out My Primary Group Membership?

Type the following command:
$ getent group userName
$ getent group vivek
Sample outputs:

In this example, user vivek has group id # 1000 and has group name vivek for primary group membership.

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How To List All Users and Groups in Linux

Users and group files are important for Linux. Normal users will interact with Linux systems by using credentials provided in the user ad group file.

Print User File Named passwd

We can get content of the user file like below. This file provides usernames home directories and shell information.

Print User File Named passwd

As we can see each line of the output provides the user name, user id, user group, user shell, user home path etc.

Print Only Usernames

We can print only usernames by filtering other columns like below.

Print Only Usernames

Print Users Who Have Login

By default normal users will login to the Linux box. But in some cases service users do not need to login Linux system. This is also a security measure. We can list users who do not have login right with the following command. This login information is stored in the /etc/passwd file.

Print Users Who Have Login

Print Users Who Have Home Directories

We can print only users who have home directories in /home. This command will first look in to the passwd to list users how have /home and then print only user names from result.

Print Users Who Have Home Directories

Print Group File

Linux users have primary and secondary groups. These group names are stored in the /etc/group file. We can print this group information and assigned user with cat command. For more details read following tutorial.

Print Only Group Names

We can print only group names by cutting other column like below.

Print Only Group Names

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User Groups in Linux

I have heard that Linux have groups. I wonder that how can use groups in Linux ? Linux user groups are used to groups users so for privilege and permission issues can be solved for multiple users easily. For example if we have a file and want to read access for 47 Linux users we can use groups mechanism to group these users and give access to the newly created group.

List Current User Groups

First thing we will do is listing user groups in a Linux system. We can list current user group like below

List Current User Groups

We can see that current user is joined groups like ismail adm sudo etc.

List All Groups

But if we want to list all groups those exists in Linux system we can use following command.

List All Groups

Create Group

We can create new group to add user. New group creation can be done like below.

• We have added group named test

Remove Group

Removing an existing group can be done with groupdel method.

• Remove group named test

Group File

Group file is the database used by groups. Actually it is a text file like below.

Group File

• And it is generally resides in /etc/group
• For the first like root is group name
• x is the password where it is stored in /etc/gshadow
• 0 is the group id

Add User To the Group

We can add existing user to the existing group by using usermod command

• usermod -a is command to add user to group
• -G root is used to specify group
• ismail is the user name

Remove User From Group

We can remove existing user to the existing group by using usermod command

• usermod is command to remove user from group
• -G root is used to specify group
• ismail is the user name

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How to List All Users of a Group in Linux

I have already shown you to list all the users in Linux command line. This quick tip is related and yet different from that.

I presume that you are a bit familiar with the concept of groups and users in Linux. There are several groups and a variety of users in a Linux system. A group can have multiple members while a user can be a member of several groups.

You can check which groups a particular user belongs to and you can also find all the users of a group.

List all users of a group in Linux

In this quick tutorial, I’ll show you different ways to list users in a group in Linux command line.

1. List members of a group in Linux using /etc/group file

The group information is contained in the file /etc/group. You can view the content of this file and look for the information about the members.

Normally, this file has entry in the following format:

Here’s the explanation of the fields:

• adm is the group name
• x represents password field (you won’t see password in clear text of course)
• 4 is the Group ID aka GID
• syslog and abhishek are the users belonging to the group adm

If you find manual searching for a group in the file difficult, you can use a combination of the grep command and the cut command.

The above command looks for all the lines starting with the specified group name and then the cut command extract the fourth column separated with : delimiter. The result is just the name of the group members.

2. List group members in Linux with getent command

getent is a multipurpose command that is used to query from database files in the /etc directory. So you can use it to query the /etc/group file and get the users of the specified group in the following manner:

This will display the line matching the group name and in here you can see the members of the group:

3. List users in a group using ‘members’ command

There is a tiny command line tool that simplifies the process of listing all the members of a specific group.

The members command is usually not installed in all the systems so you have to install it on your own.

On Debian/Ubuntu based systems, you can install it using the following command:

If the command is not found in Ubuntu, you should enable the universe repository and try it again.

Once you have the command installed, you can run it like this:

For example, if you want to check which users have sudo access, you can use the members command like this:

And the output will list all the users of the sudo group.

That’s it…

See, it was absolutely simple to get the users belonging to a group. You learned three ways to do it.

Which method did you like the most? Or, do you use some other way to list group members in Linux? Why not share it with us here?

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How to List All User Groups on Ubuntu 18.04 | 16.04 with Examples

This brief tutorial shows students and new users how to list groups on Ubuntu 18.04 | 16.04 Linux systems.

If you’re a student or new user looking for a Linux system to start learning on, the easiest place to start is on Ubuntu Linux OS. It’s a great Linux operating system for beginners.

Ubuntu is an open source Linux operating systems that runs on desktops, laptops, server and other devices.

Students and new users will find that Linux isn’t so different than Windows and other operating systems in so many ways, especially when it comes to use the system to get work done.…

Both Ubuntu and Windows systems allow you to be productive, easy to use, reliable and enable you to install and run thousands of programs from gaming to productivity suite software for individuals and businesses.

However, when you’re learning to use and understand Ubuntu Linux, you should also learn how to use the command line to terminal. Most Linux users can do some basic command line tasks. This tutorial is going to show you how..

This post shows you how to perform a basic task of listing groups on Ubuntu Linux.

When you’re ready to learn how to list groups on Ubuntu, follow the steps below:

Linux Groups:

There are two types of groups users can be assigned to: One is a primary and the other a secondary group which grants privileges to user to access certain resources.

Below is how a typical Linux user account is added and assigned group memberships:

User — A user has an account must belong to one primary group. Typically the the user’s primary group is also named after the user account name.
Primary Group — The primary group is created at the same time the user account is created and the user is automatically added to it. File created by the user automatically belongs to the user group.
Secondary Group — This group is not required and only there to give users access to other resources they’re don’t already have access to. Users can belong to none or as many secondary groups are possible.

The primary user’s group is stored in the /etc/passwd file and the supplementary groups, if any, are listed in the /etc/group file.

List User Groups using groups command

Now that you know the types of groups for users, you can use the groups command to find the groups a user belongs to. Running the groups command without any arguments, will list all the groups the user belongs to.

Should output all the group the account richard belongs to. The first group with same name as the user account name is the primary group.

To list all the groups a user belongs, add the username to the groups command

This should output same as above

List User Groups using the id command

One can also use the id command to list groups information about specified user. It prints user and group information for the specified USER,

The command will show the username (uid), the user’s primary group (gid), and the user’s secondary groups (groups)

Should output the line below:

List Group Membership using the getent command

If you want to know who are members of a particular group, use the getent command. This command gets entries from administrative database.

To get a membership of the cdrom group, run the command below

getent group cdrom

This should output all the users who have access to the cdrom group.

Listing All Groups

To list the entire groups on Ubuntu, run the command below

That should output all the groups on each line

Congratulations! You have learned how to list groups on Ubuntu Linux.

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