Linux listing all groups

Linux Show All Members of a Group Command

Linux Show All Members of a Group Commands

Tutorial details
Difficulty level	Easy
Root privileges	Yes
Requirements	None
Est. reading time	1m

1. /etc/group file – User group file
2. members command – List members of a group
3. lid command (or libuser-lid on newer Linux distros) – List user’s groups or group’s users

There are two types of groups in Linux:

• Primary group – is the main group that is associated with user account. Each user is a member of exactly one primary group.
• Secondary group – used to provide additional rights to user. For example, access to the dvd/cdrom drive can be granted with help of cdrom group.

Linux: List all members of a group using /etc/group file

Use the grep command or cat command/more command as follows:
$ grep ‘grpup-name-here’ /etc/group
$ grep ‘ftponly’ /etc/group
$ cat /etc/group
$ less /etc/group
$ grep -i —color ‘ftponly’ /etc/group

We can also type the compgen command or getend command to list all group names on Linux:
$ compgen -g
$ getent group
To get just a list of all members of a group called ftponly , type the following awk command:

Display group memberships for each Linux user

Want to see group memberships for each given USERNAME under Linux? The syntax is as follows for the groups command:
groups
groups
groups vivek
The following outputs indicates that the user named ‘vivek’ is part of four groups including ‘vivek’ primary group:

Linux List all members of a group using members command

Warning: members command is not installed on most Linux distros. Use yum command or apt-get command/apt command to install the same:
$ sudo apt-get install members

To outputs members of a group called ftponly, enter:
$ members
$ members ftponly

Fig. 01: members command in action to list members in a group

How to list all users in a Linux group using lid command

You can displays information about groups containing user name, or users contained in group name using lid command as follows.

Warning: lid command is not installed on most distros. Use yum command or apt-get command to install the same:
$ sudo apt-get install libuser

To see users contained in group named ‘ftponly’:

# lid -g ftponly
Please note that newer version of libuser renamed the lid command to libuser-lid . Thus, use it as follows:
$ sudo libuser-lid -g ftponly
Sample outputs:

To show information about groups containing user named ‘nixcraft’:

Use lid command or libuser-lid command on Linux to show all members of a group named nixcraft:
# lid nixcraft
OR
$ sudo libuser-lid nixcraft
Sample outputs:

See lid command man page for more information.

How to list groups in Linux

To see all users, run less command/more command:
less /etc/group
OR
more /etc/group
Another option is to type the following getent command:
getent group
For example, locate the members of a group with the name vboxusers, run:
getent group vboxusers
Sample outputs indicating vivek and raj users are part of vboxusers group:

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Finally, you can use the id command to display real and effective user and group IDs:
id
id vivek
id -nG raj # show all group IDs for raj user
id -ng raj # show only effective group ID for raj user

Conclusion

Now you know how to use various Linux commands to show all members of a group. I suggest you read the man pages for more info by typing the following man command:
$ man libuser-lid
$ man members

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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 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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How to list all groups a user is a member of

Before delving into the 5 ways, let’s first understand some basics:

Adding a user to an existing group is one of the typical tasks of a Linux administrator.

A group is a collection of users. The main purpose of the group is to define a set of privileges to their members within the group.

It can be a difficult task if you want to assign a set of privileges to multiple users without a group. This is where the group comes in handy.

All system users are listed in the /etc/passwd file, the groups are listed in the /etc/group file, and the actual password is stored in the /etc/shadow file.

No matter what command we use, it will fetch information from these files.

There are two types of groups in Linux:

• Primary Group
• Secondary Group

What is primary group?

The primary group is the main group associated with the user account. Each user must be a member of a single primary group.

What is secondary group?

The secondary or supplementary group is used to grant additional rights to the user. Each user can become a member of multiple secondary groups.

What is /etc/passwd file

“/etc/passwd” is a text file containing every user information that is required to login to the Linux system. It maintains useful information about users such as username, password, user ID, group ID, user information, home directory and shell.

Each user profile in the password file is a single line with seven fields as shown below:

What is /etc/group file

“/etc/group” is a text file that defines which groups a user belongs to. We can add multiple users in the same group.

Linux has three permission levels which define how users can access it. These levels are user, group and others, which controls a users access to other users’ files and folders.

/etc/group file maintains useful information about the group such as group name, group password, group ID (GIT) and membership list. Each group details is shown in a single line with four fields as shown in the ‘method #5’ listed below.

The following seven commands will help you find out which groups a user belongs to in Linux.

• groups: Show All Members of a Group.
• id: Print user and group information for the specified username.
• lid or libuser-lid: It display user’s groups or group’s users.
• getent: Get entries from Name Service Switch libraries.
• compgen: compgen is bash built-in command and it will show all available commands for the user.
• members: List members of a group.
• /etc/group file: Also, we can grep the corresponding user’s groups from the /etc/group file.

Now let’s delve into the 5 methods which can be used to find the list of groups a user is part of in Linux:

Method-1: Using groups command

The ‘groups’ command is widely used by Linux admin to list all groups a user is a member of. It prints the information of the given user’s primary and supplementary groups as shown below:

Run ‘groups’ command without any arguments to display the list of groups associated with the current user as shown below:

Method-2: Using id command

The id command stands for identity. It prints real and effective user, group, and supplementary group information such as username, UID, group names and GUID as shown below:

Just run the ‘id’ command to view group information about the current user as shown below:

Method-3: Using lid command

The lid or libuser-lid command displays information about groups containing user name, which requires sudo privileges.

You should run the libuser-lid command instead of the lid on newer systems.

Method-4: Using the getent command

The getent command displays entries from databases supported by the Name Service Switch libraries, which are configured in ‘/etc/nsswitch.conf’:

The above command shows the group name and all other members associated with that group. Use the below customized command format to print only groups for a given user:

Run the below command to print only the primary group information of the user:

Method-5: Using the ‘/etc/group’ file

User groups information can be filtered from the ‘/etc/group’ file using grep command as shown below:

Use the below customized command format to print only groups for a given user:

Bonus Tip-1: Find out all groups using compgen command

Compgen is a bash built-in command that displays all groups in the Linux system:

Bonus Tip-2: Listing members of a group using member command

The member command allows you to list members of a group in Linux:

Closing Notes

In this guide, we have shown you several commands to list all groups a user is a member of in Linux.

If you have any questions or feedback, feel free to comment below.

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