How to List Users in Linux

In this tutorial, we’ll be going over how to list the users that have been created on your Linux system. This applies for all distributions, and is very easy to do.

The users on your system can be either normal “human” users or system users. The normal users are usually other people that can log in and interact with your server, while the system users are used to start non-interactive background services. You might even create users for certain software platforms to have a user that grants them access to certain files and directories. Let’s begin.

Step 1. Connect to your server

To connect to your server via SSH as the root user, use the following command:

ssh root@IP_ADDRESS -p PORT_NUMBER

and replace “IP_ADDRESS” and “PORT_NUMBER” with your actual server IP address and SSH port number. Of course, you can also replace root with the username of any user you’d like, as all users can view the list of users on the system.

Step 2. The /etc/passwd file

In Linux, there isn’t any specific command that can list all users in your system. However, there is still a way to extract this information from our system. One important file that stores user information in your system is the /etc/passwd file.

The /etc/passwd file is a text file that stores all of the required information about all of the users that exist on our system.
Each entry in this file can have up to seven fields (separated by the colon “:” symbol) and each field contains some important information about that user. Here is an example of one entry for a user called “linux-user” stored in /etc/passwd:

linux-user:x:1000:1000:Linux User:/home/linux-user:/bin/bash

And here is an explanation of each of the fields in this entry:

1. Username – this is the name of the user, in our example “linux-user”
2. Password: this field contains the encrypted password of the user, marked with “x”. The encrypted password is stored in the /etc/shadow file in our system and can only be accessed by the root user.
3. User ID number (UID) – this field contains a unique number for each user. The number 0 is reserved for the root user
4. Group ID number (GID) – this is the ID number of the group, which is stored in the /etc/group file
5. User Info: this field contains all additional user information such as the user’s real name, phone numbers and other information.
6. Home Directory: this field contains the path of the user’s home directory. In our example, the home directory of the “linux-user” user is /home/linux-user
7. Login shell: this field contains the path of the user’s login shell, for example /bin/bash

3. List all users on your Linux system

Now that we know about the existence of the /etc/passwd file and the information it contains, we can simply use the cat command to print all the contents of this file. You can then look at the first field of each entry which shows the name of each user in your system:

cat /etc/passwd

Output example:

root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
. . .
. . .
sshd:x:104:65534::/var/run/sshd:/usr/sbin/nologin
mysql:x:109:114:MySQL Server,,,:/nonexistent:/bin/false
linux-user:x:1000:1000:Linux User:/home/linux-user:/bin/bash

If you want to list only the first field for each user, which contains the actual username, you can use the cut or the awk command. For example:

cut -d: -f1 /etc/passwd

or

awk -F: '{ print $1}' /etc/passwd

Both commands will give you the following output:

root
daemon
bin
sys
sync
games
man
lp
mail
. . .
. . .
sshd
mysql:
linux-user

Another way to list all users in your Linux system is with using the getent command.

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

This file also contains the passwd database, so you can now use the following command again where you will get the list of all entries included in the passwd database:

getent passwd

How to Find if a Specific User Exists in Your System

Instead of listing all users, you may also want to check if any specific user exists on your Linux server. To do this, you can combine one of the previous commands with the grep command. For example, if you want to check whether the “linux-user” user exists on your server, you can type the following command:

cat /etc/passwd | grep linux-user

If the user exists, the following output should be displayed on your screen:

linux-user:x:1000:1000:Linux User:/home/linux-user:/bin/bash

By this point, you now know how to see what users exist on your server, as well as search for a specific user on your server.

Of course, if you are using one of our Managed VPS Support services, you can simply ask our expert Linux admins to help you and give you a list of all users on your Linux VPS, along with any other system-related questions or requests. They are available 24×7 and will take care of your requests immediately.

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