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Learn how to easily extract a user list from Linux using Bash, formatting it with new lines for better readability.
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How to List Users in a Text File with New Line Formatting in Bash

When working with Linux systems, you might often find yourself in need of a clear list of users. You might try the simplest command, like listing the /home directory, but this outputs all users on a single line, which can be quite messy. Instead, what if you wanted them to appear one per line, making it visually more accessible? In this guide, we'll walk you through an effective method to achieve this using Bash.

The Problem: Getting Users into a Clear Format

Suppose you run the command below:

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This command provides a simple list of user directories—all concatenated into a single line like this:

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However, we want to transform it into this aesthetically pleasing format:

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To turn this vision into a reality, let's explore a better approach using the /etc/passwd file, which contains essential information about every user on the system.

The Solution: Using /etc/passwd to Extract Users

Understand the /etc/passwd File

The /etc/passwd file contains user account information and can be a treasure trove for gathering user details. However, this file also includes system accounts (which you might not need), hence we’ll focus on user accounts within a certain range of User IDs (UIDs).

Step 1: Identify UID Range

First, we need to find out the UID_MIN and UID_MAX for your distribution. This can usually be done by checking the /etc/login.defs file:

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The expected output might look something like this:

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This tells us that user accounts on this system typically start from UID 1000 and go up to 60000.

Step 2: Extract Usernames

Once you have determined the UID limits, you can extract the username in a more readable format using awk:

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Here’s what each part does:

-F: sets the field separator to a colon, which is what separates each field in the /etc/passwd file.

The condition '$3 >= 1000 && $3 <= 60000' filters out user accounts based on their UID ranges.

{ print $1 } prints the first field, which is the username.

Step 3: Save to File

If you want to save this nicely formatted list to a text file, simply redirect the output to a filename of your choice like this:

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Now your users.txt file will contain each username listed on a new line, creating a much more organized and clean look.

Conclusion

In summary, by utilizing the /etc/passwd file and a few simple bash commands, you can easily produce a well-structured list of users on your Linux system. This shouldn’t only enhance readability but also ensure you capture only the relevant user accounts, leaving out system accounts cluttering up your list.

Now you are equipped with the knowledge to effortlessly extract and format user data. Happy scripting!