Linux user from terminal

Is there a command to list all users? Also to add, delete, modify users, in the terminal?

I need a command to list all users as well as commands to add, delete and modify users from terminal — any commands that could help in administrating user accounts easily by terminal.

10 Answers 10

To list

To list all local users you can use:

To list all users capable of authenticating (in some way), including non-local, see this reply.

Some more useful user-management commands (also limited to local users):

To add

To add a new user you can use:

sudo adduser new_username

sudo useradd new_username

To remove/delete

To remove/delete a user, first you can use:

Then you may want to delete the home directory for the deleted user account :

Please use with caution the above command!

To modify

To modify the username of a user:

usermod -l new_username old_username

To change the password for a user:

To change the shell for a user:

To change the details for a user (for example real name):

To add a user to the sudo group:

And, of course, see also: man adduser , man useradd , man userdel . and so on.

Radu forgot to mention sudo chfn which changes user details (for example real name). I tried to add this as a comment, but I got error telling me that I must have +50 reputation to do so.

I think that it should be underlined that the correct answer to the linked question is askubuntu.com/a/381646/16395 — otherwise you have to take into account the GID/UID Ubuntu policies by hand. The accepted answer is not so clear.

sudo userdel DOMAIN\\johndoe gives me the error: «userdel: cannot remove entry ‘DOMAIN\johndoe’ from /etc/passwd — I looked in /etc/passwd and they’re not even in there, likely because it’s a «domain» account?

@00fruX Yeah. If you’re using a centralised user database you’re going to need to deal with it directly.

Just press Ctrl + Alt + T on your keyboard to open Terminal. When it opens, run the command(s) below:

less /etc/passwd more /etc/passwd 

@nux A bit late to the party, but from command line use adduser instead, useradd should be limited to scripts where the author really really knows what he is doing.

The easiest way to get this kind of information is getent — see manpage for the getent command . While that command gives the same output as cat /etc/passwd it is useful to remember because it will give you lists of several elements in the OS.

To get a list of all users you type (as users are listed in /etc/passwd )

To add a user newuser to the system you would type

to create a user that has all default settings applied.

Bonus: To add any user (for instance anyuser) to a group (for instance cdrom) type

sudo adduser anyuser cdrom 

You delete a user (for instance obsolete) with

If you want to delete his home directory/mails as well you type

sudo deluser --remove-home obsolete 

sudo deluser --remove-all-files obsolete 

will remove the user and all files owned by this user on the whole system.

It’s useful to remember that getent doesn’t just print the output of users in /etc/passwd but all users in all configured userdb backends on a given system, whether it’s /etc/passwd or LDAP, etc.

@MarcinKaminski is right, it also prints users setup in SSO systems who have access to the server. this answer is the the best one, with getent passwd being the right command

This should get, under most normal situations, all normal (non-system, not weird, etc) users:

awk -F'[/:]' '= 1000 && $3 != 65534) print $1>' /etc/passwd 

• reading in from /etc/passwd
• using : as a delimiter
• if the third field (the User ID number) is larger than 1000 and not 65534, the first field (the username of the user) is printed.

This is because on many linux systems, usernames above 1000 are reserved for unprivileged (you could say normal) users. Some info on this here:

A user ID (UID) is a unique positive integer assigned by a Unix-like operating system to each user. Each user is identified to the system by its UID, and user names are generally used only as an interface for humans.

UIDs are stored, along with their corresponding user names and other user-specific information, in the /etc/passwd file.

The third field contains the UID, and the fourth field contains the group ID (GID), which by default is equal to the UID for all ordinary users.

In the Linux kernels 2.4 and above, UIDs are unsigned 32-bit integers that can represent values from zero to 4,294,967,296. However, it is advisable to use values only up to 65,534 in order to maintain compatibility with systems using older kernels or filesystems that can only accommodate 16-bit UIDs.

The UID of 0 has a special role: it is always the root account (i.e., the omnipotent administrative user). Although the user name can be changed on this account and additional accounts can be created with the same UID, neither action is wise from a security point of view.

The UID 65534 is commonly reserved for nobody, a user with no system privileges, as opposed to an ordinary (i.e., non-privileged) user. This UID is often used for individuals accessing the system remotely via FTP (file transfer protocol) or HTTP (hypertext transfer protocol).

UIDs 1 through 99 are traditionally reserved for special system users (sometimes called pseudo-users), such as wheel, daemon, lp, operator, news, mail, etc. These users are administrators who do not need total root powers, but who perform some administrative tasks and thus need more privileges than those given to ordinary users.

Some Linux distributions (i.e., versions) begin UIDs for non-privileged users at 100. Others, such as Red Hat, begin them at 500, and still others, such Debian, start them at 1000. Because of the differences among distributions, manual intervention can be necessary if multiple distributions are used in a network in an organization.

Also, it can be convenient to reserve a block of UIDs for local users, such as 1000 through 9999, and another block for remote users (i.e., users elsewhere on the network), such as 10000 to 65534. The important thing is to decide on a scheme and adhere to it.

Among the advantages of this practice of reserving blocks of numbers for particular types of users is that it makes it more convenient to search through system logs for suspicious user activity.

Contrary to popular belief, it is not necessary that each entry in the UID field be unique. However, non-unique UIDs can cause security problems, and thus UIDs should be kept unique across the entire organization. Likewise, recycling of UIDs from former users should be avoided for as long as possible.

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User Management in Linux: How to do it using the terminal?

User Management in Linux: How to do it using the terminal?

Without a doubt, one of the first steps that is usually done when installing and using any Operating systemIncluding GNU / Linux, for both server computers and desktop computers, is the creation of user accounts.

And whether they are used graphical tools (GUI) or terminal tools (CLI) to manage user accounts in Linux, the ideal will always be to know and master these tasks through the command line. For this reason, today we will address the topic of «User Management in Linux».

And as usual, before entering fully into today’s topic on the “Linux User Management”, specifically about create and delete user accounts, we will leave for those interested the following links to some previous related publications. In such a way that they can easily explore them, if necessary, after finishing reading this publication:

» UNIX/Linux operating systems offer a REAL multi-user environment, in which many users can work simultaneously on the same system and share resources such as processors, hard drives, memory, network interfaces, devices inserted in the system, etc. For this reason, System Administrators are obliged to continuously manage system users and groups and to formulate and implement a good administration strategy. » . Management of local users and groups — SME networks

Linux User Management: Useful Commands

useradd and adduser Commands

As we stated at the beginning, generating users is usually an essential and initial task in Operating Systems, included GNU / Linux. Since, many times, the first user is generated during the installation and the secondary ones through some graphical interface tool.

Meanwhile, in other cases, the terminal or console is usually used. And in this last case, that is, through the terminal, 2 commands can be used to generate users. Which are: «useradd» y «aduser».

And how are the useradd and adduser commands different?

The fundamental difference between the two is that «useradd» is a command which directly runs an OS binary, while «adduser» is a script made in perl which uses the «useradd» binary. For this reason, the «adduser» command has the greatest advantage of being able to generate the user’s home directory (/home/usuario/) automatically, while the «useradd» command requires the use of an additional option (parameter — m).

However, «aduser» not being a kernel command GNU / Linux Operating System employee, it may not work as well, or the same, in all distributions in which it is present. Consequently, the use of «useradd» over «adduser» is always recommended. The same goes for the commands, «userdel» and «deluser».

Practical examples of the commands: useradd, adduser, userdel and deluser

command order: «sudo useradd -m usuario1»

• Action to execute: 2.- Create a system user, without including your personal directory.

command order: «sudo useradd usuario2»

command order: «sudo adduser usuario3»

• Action to execute: 4.- Delete a user from the system, including his personal directory.

command order: «sudo userdel -r usuario1»

• Action to execute: 5.- Delete a user from the system, not including his personal directory.

command order: «sudo userdel usuario2»

• Action to execute: 6.- Delete a user from the system, not including his personal directory.

command order: «sudo deluser usuario3»

Other commands related to user account management

Also, just as they can be used the «useradd», «adduser», «userdel» and «deluser» commands in a simple way to create and delete user accounts within the operating system, they can also be used together with their multiple options (parameters) for more diverse and complex cases. And there are also other associated commands that allow us to execute complementary tasks on user accounts.

To do this, below we will see some specific and more advanced tasks that demonstrate the aforementioned:

command order: «sudo usermod -a -G sudo usuario1»

command order: «sudo passwd usuario1»

command order: «sudo useradd -d /home/u1home usuario1»

command order: «sudo useradd -m -d /opt/usuario1 usuario1»

command order: «sudo deluser usuario1 grupo1»

command order: «finger usuario1»

Finally, and in case you want or need to go deeper into the «User Management in Linux», we recommend exploring the following links:

Your Order

In short, bring “User Management in Linux” via terminal or console, it can be really a simple and easy task. Above all, if you have useful, current and official information at hand, about the commands related to the administration of user accounts inside of the GNU / Linux Operating System, both for servers and desktop computers.

We hope that this publication is very useful for the entire «Comunidad de Software Libre, Código Abierto y GNU/Linux» . And don’t forget to comment on it below, and share it with others on your favorite websites, channels, groups or communities of social networks or messaging systems. Finally, visit our home page at «FromLinux» to explore more news, and join our official channel Telegram from DesdeLinux, West group for more information on the subject.

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