Linux get users from group

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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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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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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