Linux List Users - Shell/Bash

Introduction

In Linux, there are several ways to list the users of the system using shell or bash commands. This article will provide you with different methods to accomplish this task.

Method 1: Using the cat /etc/passwd command

The /etc/passwd file contains a list of all users on the system. Each line in this file represents a user and contains information such as username, user ID, group ID, home directory, and shell. You can use the cat command to display the contents of this file and filter out the required information using other shell commands.

For example:

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

This command reads each line of the /etc/passwd file, separates the fields using the : delimiter (specified by the -F option of awk), and prints the first field (username) using the {print $1} command of awk. This will output a list of all usernames.

Method 2: Using the cut -d: -f1 /etc/passwd command

Similar to the previous method, you can also use the cut command to extract the username field from the /etc/passwd file. The -d option specifies the delimiter (in our case, :) and the -f option specifies the field to cut (in this case, the first field).

For example:

cut -d: -f1 /etc/passwd

This command will give you a list of all usernames on the system.

Method 3: Using the getent passwd command

The getent command is used to get entries from administrative databases, including the user database. By specifying the passwd database, you can list all usernames.

For example:

getent passwd | cut -d: -f1

This command combines the getent and cut commands to extract the username field from the passwd database.

Method 4: Using the /etc/passwd file directly

If you prefer a simple way to display the usernames without using any commands, you can directly view the /etc/passwd file using a text editor or the less command.

For example:

less /etc/passwd

This command will open the /etc/passwd file in the less pager, allowing you to scroll through the file and view all usernames.

Conclusion

These are some of the methods you can use to list users in Linux using shell or bash commands. Depending on your requirements and preferences, you can choose any of these methods to retrieve the desired information.