Linux show group members

How can I find out which users are in a group within Linux?

I’ve recently been creating new users and assigning them to certain groups. I was wondering if there is a command that shows all the users assigned to a certain group? I have tried using the ‘groups’ command however whenever I use this it says ‘groups: not found’

That is the groups command. It is unlikely that you do not have it on Linux, since it is part of coreutils.

11 Answers 11

I prefer to use the getent command .

Since getent uses the same name service as the system, getent will show all information, including that gained from network information sources such as LDAP.

So for a group, you should use the following .

getent group name_of_group 

where name_of_group is replaced with the group you want to look up. Note that this only returns supplementary group memberships, it doesn’t include the users who have this group as their primary group.

There are a whole lot of other lookups that you can do . passwd being another useful one, which you’ll need to list primary groups.

The other answers doesn’t apply if you are not administrator and the group info is stored in other server.

This could be really confusing probably because of primary/secondary difference. I think this should be avoided in favor of sudo lid -g .I have a system where this answer lists 8 users in a group whereas sudo lid -g lists 10.

grep '^group_name_here:' /etc/group 

This only lists supplementary group memberships, not the user who have this group as their primary group. And it only finds local groups, not groups from a network service such as LDAP.

This could be really confusing probably because of primary/secondary difference. I think this should be avoided in favor of sudo lid -g .I have a system where this answer lists 8 users in a group whereas sudo lid -g lists 10.

This should NOT be the accepted answer. Modern Linux installations have multiple sources for user/group information — not just local /etc/passwd and /etc/group — e.g. nsswitch or sssd . Use getent passwd for user info & getent group for group information — this will cover all modern Linux configurations.

Easier to do groups [username]

If you want to list all local users and their local groups you can do

cat /etc/passwd | awk -F’:’ ‘< print $1>‘ | xargs -n1 groups

If you get «groups: command not found», it is likely you’ve edited your environmental path for the worse, to reset your path do PATH=$(getconf PATH)

It works for a particular group if | grep is added and gives the correct answer unlike getent group name_of_group or grep ‘^group_name_here:’ /etc/group

Instead of cat /etc/passwd , you should use gentent passwd so users in nis/ldap would still be listed. The only drawback is that it can take quite a while.

groupmems -g groupname -l

lists all users in the named group.

Note that groupmems is part of the shadow utils used on most Linux distros, however groupmems is currently absent from Debian and derivative (a bug now fixed but not included in any release yet (as of Nov 2016))

Also note that groupmems only deals with groups in /etc/group (not the ones in LDAP or other user database) and requires superuser privileges as it tries to open /etc/gshadow.

Despite the caveats mentioned above, this command is ideal for certain situations because it doesn’t require additional parsing of the output (i.e. cut and friends).

This could be really confusing probably because of primary/secondary difference. I think this should be avoided in favor of sudo lid -g . I have a system where this answer lists 8 users in a group whereas sudo lid -g lists 10.

groups command prints group memberships for a user. You can use lid command to list users in a group like:

Update: On Debian based distributions the command name differs as libuser-lid . Both commands are provided by libuser package as @chris-down mentioned.

$ sudo libuser-lid -g lpadmin kadir(uid=xxxx) 

What’s more, on Ubuntu 20.04 LTS, lid is part of the id-utils package. After installation it turned out that this lid does not support the -g option. I understand that Kadir answered 6 years ago, but maybe it’s time to update the information given here.

@LaryxDecidua id-utils manipulates id databases, it doesn’t work with files such as /etc/group or /etc/passwd . Its lid is not at all similar to libuser ’s.

I am surprised nobody mentioned

This command will give a list of groups the user is in.

Because — contrary to the title — the questioner wanted to know the users within a given group, not the groups of a given user, as detailed in the question. I now rephrased the title to match the contents.

Even though , is it different from the actual question, everyone will find this too as a useful information , I bet !

cut -d: -f1,4 /etc/passwd | grep $(getent group | cut -d: -f3) | cut -d: -f1 

I disagree. Because it reads users in /etc/passwd, this will not work with other nsswitch modules that access LDAP etc.

Didn’t work correctly for me: I got 4 members in a group whereas sudo lid -g lists 8. @Bhavik The accepted answer is not correct either.

Works nicely, especially if cut -d: -f1,4 /etc/passwd is replaced with getent passwd | cut -d: -f1,4 . As many people have pointed it out, getent will query non-local information sources.

Some will tell you to install libuser (for ‘lid’) or members (for ‘members’). But building upon the answer https://unix.stackexchange.com/a/349648/77959 which handled this issue with login group membership I found another group not being covered by that script. So — here’s the best of both approaches combined:

#!/bin/bash if [ $# -eq 1 ]; then gid=`getent group "$1"|cut -d: -f3` list_a=`cut -d: -f1,4 /etc/passwd | grep ":$gid$" | cut -d: -f1` list_b=`getent group "$1"|cut -d: -f4|sed 's/,/\n/g'` echo -e "$list_a\n$list_b"|grep -v "^$"|sort|uniq else echo "pass me a group to find the members of" fi 

It worked correctly on my system unlike answers involving getent or grep ‘^group_name_here:’ /etc/group

OP phrased the question to exclude the possibility of using the groups command. Since that is part of coreutils on Linux, either (a) it was removed, or (b) OP is mistyping the name.

OP could have used groups like this, for instance:

for name in $(cut -d: -f1 /etc/passwd);do groups $name|grep -w sudo|awk '';done 

One suggested answer just grep’s for the group name in /etc/group . Sometimes that works as intended.

A slightly better use of grep takes into account the syntax of /etc/group :

group_name:password:GID:user_list 

so that only the part before the first colon is a valid group-name. A plain grep without regard to syntax can (and will) pick up misleading matches from the file. Use regular expressions to make the grep match exactly what is needed:

grep -E '^users:' /etc/group |sed -e 's/^.*://' 

or using a shell variable:

grep -E '^'$groupname':' /etc/group |sed -e 's/^.*://' 

However, that only lists those not in a default group. To add those, you need to take into account the password file, e.g., by extracting the group-id number from /etc/group , and printing the users whose default group matches from /etc/passwd , e.g.,

You could do the same thing using just grep and sed, but it is more work than using awk.

Another suggested answer proposed using getent , which also is likely to be on a Linux machine (with Debian, it is part of GNU libc). However a quick check of that shows it providing only the /etc/group content.

I (like most) do not have libusers or lid installed, so I cannot comment on whether it satisfies OP’s conditions.

There is also the id program, which gives group information. Someone might expand on that as a possible answer.

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Mastering Linux User and Group Management: A Comprehensive Guide to Show Group Members in Linux

Learn how to show group members in Linux using various commands such as /etc/group file, members, lid, and getent, and best practices for managing users and groups in Linux. Start securing your Linux system today!

• Using the /etc/group file
• Using the members command
• Using the lid command
• Using the getent command
• Managing users and groups in Linux
• Other quick examples of code to show group members in Linux
• Conclusion
• How do I show group members in Linux?
• What command displays the group memberships for a user Linux?
• How to show group ID in Linux?
• How do I see all groups on a Linux server?

As a system administrator, managing users and groups is a crucial part of working with Linux. In this comprehensive guide, we will explore different ways to show group members in Linux. We will cover using the /etc/group file, the members command, the lid command, and the getent command. Additionally, we will discuss best practices for managing users and groups in linux .

Using the /etc/group file

The /etc/group file defines the groups on the system and can be used to list all groups present on the system. To display the members of a group, simply open the file and search for the group name. To list all groups on the system, use the cat command followed by the /etc/group file path. This method is useful when you want to quickly check the group memberships of a particular group.

Here is an example of how to list all groups on the system using the /etc/group file:

To display the members of a particular group, use the following command:

Replace groupname with the name of the group you want to check.

Using the members command

The members command is a simple way to list all users in a group. To use this command, simply enter members followed by the group name. This method only works if the group is stored in the /etc/group file.

Here is an example of how to list all users in a group using the members command:

Replace groupname with the name of the group you want to check.

Using the lid command

The lid command is another way to show group members in Linux. It can display a list of users or groups based on the specified criteria. To list all users in a group, use the lid command followed by the group name. This method is useful when you want to see a list of users in a specific group.

Here is an example of how to list all users in a group using the lid command:

Replace groupname with the name of the group you want to check.

Using the getent command

The getent command can provide a unified view of users or groups. To list all users in a group, use the getent group command followed by the group name. This command can also be used to list all groups on the system. This method is useful when you want to see a complete list of all users or groups on the system.

Here is an example of how to list all users in a group using the getent command:

Replace groupname with the name of the group you want to check.

Managing users and groups in Linux

To add a user to a group, use the usermod command followed by the -aG option and the group name. For example, to add a user named username to a group called groupname , use the following command:

sudo usermod -aG groupname username 

To create a new group, use the groupadd command followed by the group name. For example, to create a group called newgroup , use the following command:

To see which groups a user belongs to, use the groups command followed by the username. For example, to check which groups the user username belongs to, use the following command:

Regularly reviewing group memberships and removing users who no longer require access is a best practice for managing users and groups in linux .

Other quick examples of code to show group members in Linux

In Shell , for example, linux show groups code sample

In Shell , for instance, linux show groups

cat /etc/groupcat /etc/groups | grep # Example: cat /etc/groups | grep sudo # Output sudo:x:27:, , . # sudo : group name # x : password (encrypted for security reasons) # 27 : could be another number, represents group ID # list of users in group

In Shell case in point, linux show all group members

In Shell , in particular, linux show groups code example

Conclusion

In conclusion, managing users and groups is an essential task for any Linux system administrator. In this article, we have explored various ways to show group members in Linux, including using the /etc/group file, the members command, the lid command, and the getent command. We have also discussed best practices for managing users and groups, such as adding users to groups, creating new groups, and reviewing group memberships regularly. By following these best practices, you can ensure that your Linux system is secure and well-managed.

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