You may have heard of the / etc / passwd file on Linux. But do you know what this passwd file is for?
Linux is a multi-user operating system. To enable proper user management, the system saves the user information in the / etc / passwd File.
This guide will help you understand what the passwd file is and the important role it plays in user management on Linux.
What is / etc / passwd?
The passwd file on Linux is a configuration file that contains user details. An important feature of the passwd file is that it is an ASCII text file that users can easily edit using any text editor such as nano and vim.
While you can add and manage users directly using the passwd file, doing so is not advisable as this action is prone to typing errors and mistakes. Instead, you should use the various user administration commands such as useradd to add users to your system.
View the / etc / passwd
To view the contents of the passwd file, you can use any text editor or command tool to view files. In this guide we will be using Approx..
cat / etc / passwd
The output should be similar to the following.
Each line actually represents one user on your system. So don't be surprised to find so many users listed. Most of them are system users who control certain applications on your Linux computer. For example the user Mail is responsible for the mail application.
The / etc / passwd fields explained
From the above output it is very clear that the / etc / passwd File follows a very specific pattern.
Each user line is further broken down into seven sections or fields separated by the Colon Character (::) As follows.
1. User Name
The first field on a line represents the username or login name of the user. In the example above, the username is John.
The second field shows the encrypted password of the user. For security reasons, the passwords are saved in a separate file that cannot be read by normal users. Linux user passwords are stored in the / etc / shadow file.
Usually the password field contains a x to show that the shadow file is securely storing the password. If the field is blank, the user does not need a password to log in. To ensure general system security, every user on your system should have a password. Use the passwd command to change or manage user passwords on Linux.
3. User ID
The User ID field, commonly known as the UID, is a number used by the Linux system to identify users. Most system users have a user ID less than 1000, while regular users have IDs greater than 1000. The root The (administrative) user usually has the ID 0.
4. Group ID
The fourth field is for the group ID (commonly known as the GID). As a user ID, the GID is also a number. The group ID determines the primary group of a user. In addition, GIDs categorize all users into specific groups for ease of administration. A user can belong to several groups under Linux. To learn more about which groups a user belongs to, you can take a look at the / etc / group File.
Cat / etc / group
The next field is the GECOS field. It usually includes a user's full name and additional details like phone number or room numbers separated by commas. This field is optional and can therefore be empty.
6. Home directory
This field contains the /At home Directory assigned to the user. This is the primary directory where power user files and directories such as / Desktop and / Images. In this example, the user's home directory is under / home / john.
Having separate home directories for each user is one of the factors that enables Linux to be a true multi-user operating system.
This field contains the name of the standard shell assigned to a user. The shell is the environment in which a user can execute commands and scripts. Most Linux distributions use the Bourne Again Shell (Bash) as their default shell program.
Simplification of system administration under Linux
This guide showed you what that is / etc / passwd File on Linux and the key role it plays in managing users on your Linux system. The passwd file contains user-related information such as username, password details, home directory path, user and group IDs, etc.
As you've seen, most Linux users are usually part of a group to make it easier to manage file access and other permissions. You can add users to groups yourself if you have the necessary permissions.
Ubuntu Linux: Adding and Removing Users from Groups the Easily
Do you want to better manage users on Ubuntu Linux? The answer is to create groups and then use the Ubuntu feature to add users.
About the author
(18 articles published)
Mwiza is a professional developer of software and writes extensively on Linux and front-end programming. Some of his interests include history, economics, politics, and enterprise architecture.
By Mwiza Kumwenda
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