Linux list all user and group

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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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 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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Linux List All Users In The System Command

Table of contents

Linux list all users account using the /etc/passwd file

In order to list all users on Linux, use the cat command as follows:
$ cat /etc/passwd
Here is what I see:

Each line in the file has seven fields as follows. For example, consider the following line:
vnstat:x:131:137:vnstat daemon. /var/lib/vnstat:/usr/sbin/nologin
Where,

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• vnstat – The user name or login name.
• x – Encrypted password is stored in the /etc/shadow file.
• 131 – UID (user ID number)
• 137 – Primary GID (group ID number)
• vnstat daemon – GECOS. It may includes user’s full name (or application name, if the account is for a program), building and room number or contact person, office telephone number, home telephone number and any other contact information.
• /var/lib/vnstat – Home directory for the user.
• /usr/sbin/nologin – Login shell for the user. Pathnames of valid login shells comes from the /etc/shells file.

How to list users in Linux using pagers

Of course we can use pagers such as more/less commands as follows to view the /etc/passwd file:
$ more /etc/passwd
$ less /etc/passwd
Sample outputs:

Fig.01: List users using /etc/passwd

Linux list user names only

To list only usernames type the following awk command:
$ awk -F’:’ ‘< print $1>‘ /etc/passwd
Sample outputs:

Another option is to use the cut command:
$ cut -d: -f1 /etc/passwd

Get a list of all users using the getent command

To get a list of all Linux users you can type the following getent command:
$ getent passwd
$ getent passwd | grep tom
## get a list all users ##
$ getent passwd | cut -d: -f1
## count all user accounts using the wc ##
$ getent passwd | wc -l
One can use the compgen command on Linux to list users and other resources too:
$ compgen -u

Find out whether a user account exists in the Linux server

We can use above commands to see whether a user exists in the Linux machine as follows using the grep command:

A simplified command would be:

How to count user accounts in the Linux server

Want to get user accounts count on your system? Try the wc command as follows:
$ compgen -u | wc -l
$ getent passwd | wc -l

A Note About System and General Users

Each user has numerical user ID called UID. It is defined in /etc/passwd file. The UID for each user is automatically selected using /etc/login.defs file when you use useradd command. To see current value, enter:
$ grep «^UID_MIN» /etc/login.defs
$ grep UID_MIN /etc/login.defs
Sample outputs:

1000 is minimum values for automatic uid selection in useradd command. In other words all normal system users must have UID >= 1000 and only those users are allowed to login into system if shell is bash/csh/tcsh/ksh etc as defined /etc/shells file. Type the following command to list all login users:

To see maximum values for automatic uid selection in the useradd command, enter:
$ grep «^UID_MAX» /etc/login.defs
Sample outputs:

In other words, all normal system users must have UID >= 1000 (MIN) and UID /etc/shells file. Here is an updated code to get details:

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Tutorial requirements
Requirements	Linux
Root privileges	No
Difficulty	Easy
Est. reading time	5 mintues