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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3 Ways to List Users in Linux
Today different Operating Systems have the capability to use multiple users, each one with their settings and custom configurations to make things easier for administrators and operators to work in together on the same system.
Linux on the other hand is very strong on this matter as it allows multiple users to work at the same time on the system in an independent way. It can even allow a single user to open several sessions even from different locations in order to work on the system.
Here are some hints & tricks to handle users in Linux.
List all the users on Linux
Let’s say you want to create a sudo user in Linux. Probably, the very first thing to know is how to know what users are in my system. There are several ways you can obtain the list of users in Linux.
1. Show users in Linux using less /etc/passwd
This command allows sysops to list the the users that are locally stored in the system. It will give the listing in structured way as:
The structure in the above output goes as:
User name
Encrypted password ( x represents password is stored)
User ID number (UID)
User’s group ID number (GID)
Full name
User’s home directory
User’s Login shell (default is bash shell)
Why so many users? Which ones are ‘real’?
The list shows a lot more users than you expected because it lists all the system users too.
Now if you want to distinguish the normal users from the system users, you can refer to the User identifier (UID) number.
Generally, a normal user has UID greater or equal to 1000. This gives you a hint that the user with UID >=1000 is a normal user and users with UID
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How to List Users in Linux, List all Users Command
Home » SysAdmin » How to List Users in Linux, List all Users Command
Linux OS is unique because of its multi-user characteristic allowing multiple users on one system, at the same time. However, tracking all users is essential.
In this article, earn multiple commands to list all Linux users along with their login information. These commands work on CentOS, Ubuntu, Arch Linux, and other Linux distributions as well.
A Linux distribution installed and running
A user with sudo privileges
Access to a terminal/command line
List All Linux Users, 2 Options
List All Users in Linux with the /etc/passwd File
Details of local users can be found in the /etc/passwd file. Every line contained in the file contains the information of one user.
There are two options.
Open the etc/passwd file by typing the command:
Alternatively, you can use the less command:
Note: To display a list of the logged-on users and the information such as boot time, processes, hostnames, and more, use the who command.
List All Linux Users with the getent Command
Database entries configured in the /etc/nsswitch.conf file include the passwd database with all the usernames and login information.
To extract this data, use the command:
Both Option 1 and Option 2 will display all the users and their login information.
Each line represents one user and has seven (7) fields.
The fields are separated by : (colons) and each line includes the following information:
1. Username 2. The encrypted password (represented by x, located in the /etc/shadow file) 3. User ID number (known as UID) 4. User group ID (known as GID) 5. User full name 6. User home directory 7. The login shell (by default set to bin/bash)
How to Only List Linux Usernames
In case you don’t need all the information related to each user, you can list only the usernames on the system. There are two ways to see just the first field (the username) of each user.
Option 1: Using the awk or cut command.
To list usernames only, you can use either of the following two (2) commands:
Option 2: Using the getent command with awk and cut .
To read and display the username without any additional information using the getent command, run the following command:
Alternatively, use the command:
How to Search for Existing Linux Users
The getent command also allows you to check whether a user is present on the system.
Any of the following two commands will provide you with that information:
If the user exists, it will display login information. On the other hand, if there is no such user, there will be no output.
For example, in the image below, the query displays whether a user named example exists. The output proves that such a user exists.
System User vs Normal User
A system user is the one that creates normal users. Therefore, in this instance, the system user is the root. This user is created when you first install the Linux operating system. Additionally, you can create system users for particular applications.
On the other hand, normal users are all users that the root (or a user with sudo privileges) creates. Each normal and system user has a real login shell, home directory, as well as a user ID (UID) number. The user ID number is given automatically in the range between the minimum and maximum values.
How to Check UID_MIN and UID_MAX
If you want to check what the UID range for normal users is, use grep with the following command:
The output shows that all normal users have a UID anywhere from 1000 (UID_MIN) to 6000 (UID_MAX).
Note: Change the values in the command according to the minimum and maximum UID values for your system.
How to List Normal Users
With these numbers in mind, you ask for a list of all the users in that range with the command:
The query lists all the normal users, as seen in the image below. In this example, there are two normal users in the specified range.
After reading this guide, you should know how to list all Linux users, search for users, and find the number of Linux users in any Linux distribution ( Ubuntu, CentOS, RHEL, Debian, and Mint).
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How To List All Users In Linux
This brief guide explains how to list all users in Linux operating systems. Before getting into the topic, we will see what is /etc/passwd file. Because we depend on this file through out this guide.
A brief note about the /etc/passwd file
In Linux (and Unix in general), the basic information about each user account is stored in «/etc/passwd» file. It is nothing but a plain text file that contains the attributes of all user accounts present in a Linux system.
By default, this file is readable by all users with the help of any text or graphical programs, such as Vi, Nano, Gedit etc or with commands like «cat«.
If you open this file..
. you will see several entries like below:
Each line in the /etc/passwd file represents a single user. The root user will be listed on the top. Each line contains seven attributes or fields separated by a colon without any spaces between each field. The name of the seven fields are given below:
1. Name
The «name» field is the user’s login name that you use to login to your Linux box.
2. Password
The «password» field merely contains a letter X. Meaning — the password is encrypted and stored in a separate file called «/etc/shadow» for security purpose. The /etc/shadow can not be read by the normal users. Here the X indicates that the user has a password. If this field is empty, the user has no password, so he can login without password.
3. User ID
The «User ID» (or UID in short) indicates the user’s unique numeric identification number. The root account’s UID is 0 (zero). The numbers from 1 to 99 are reserved for system accounts. And the numbers starting from100 to 999 are reserved for normal users and groups.
4. Group ID
The «Group ID» (or GID in short) indicates the primary group identifier the user belongs to. The GID is usually the same as the UID.
5. Geckos
The «geckos» field contains the general information of a user. For example, It may contain the user’s real name. This filed might be either empty separated by two colons or it might contain multiple entries separated by commas.
6. Home directory
The «home directory» field indicates the full path of the user’s home directory, for example /home/sk. This is the directory that the user is first in when he logged into a system. The home directory usually contains programs and configurations files belonged to the user.
7. Shell
The last filed is «shell». It indicates the full path of the default shell for that user.
Now, let us take the following line as an example:
In the above line,
root — is the user name,
x — indicates the root user has password,
0 — The first 0 (zero) indicates the UID,
0 — The second zero indicates the GID,
root — It indicates the real name of the user.
/root — It is the home directory of the root user,
/bin/bash — Default shell for root user.
Hope you get a basic idea about the /etc/passwd file. Now let us get back to our topic i.e listing all users in a Linux system.
List All Users In Linux
There are couple ways to list all users in a Linux system. Here I have included all possible ways.
1. List all users in Linux using cat command
As the names says, the cat command is generally used to concatenate files and print the contents of the files.
To list all users in a Linux system using cut command, run:
This command will list all available users
Sample output:
List all users in Linux using cat command
As I mentioned already, the first field in the above entries represents the users. If you don’t want all fields but only display the user names, the following methods would help.
3. List users using cut command
The «cut» command is used to remove sections (or fields) from each line of files.
To list all users with cut command in a Linux system, run:
This command will only display the user names from the /etc/passwd file and ignore all other fields.
Sample output:
List all users in Linux using cut command
4. Print users in Linux with awk command
We can also use «awk» command to list all users in Linux.
This command will also display only the users and omit all other details.
List all users in Linux using awk command
5. View list of users with compgen
Compgen is BASH built-in to manipulate the programmable completion facilities.
To list all users using compgen, run:
6. Display all users using getent command
Another way to list the users in Linux is to use «getent» command like below:
This command will read the /etc/passwd file and lists all users in that file.
List all users in Linux using awk command
One notable advantage of getent command is it not only lists the users in the /etc/passwd file but all users in all configured userdb backends, for example LDAP, on a given system.
7. List users using the «more» or «less» commands
The more and less commands are used to open a given file for interactive reading, allowing scrolling and search.
To print all users using more or less command, run:
