Linux User Groups

Linux User and Groups Guide

Complete beginner-friendly guide to user and group management on Linux, covering Arch Linux, CachyOS, and other distributions including creating users, managing groups, permissions, and user administration.

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Table of Contents

1. User Management
2. Group Management
3. Permissions
4. User Administration
5. Troubleshooting

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User Management

Create User

Add user:

# Create user
sudo useradd -m -G wheel username

# Set password
sudo passwd username

Modify User

Modify user:

# Change shell
sudo usermod -s /bin/zsh username

# Add to group
sudo usermod -aG group-name username

# Lock account
sudo usermod -L username

# Unlock account
sudo usermod -U username

Delete User

Remove user:

# Remove user
sudo userdel username

# Remove with home
sudo userdel -r username

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Group Management

Create Group

Add group:

# Create group
sudo groupadd group-name

# Add user to group
sudo usermod -aG group-name username

Common Groups

Important groups:

• wheel: Sudo access
• audio: Audio device access
• video: Video device access
• lp: Printer access
• scanner: Scanner access

Modify Group

Modify group:

# Add user to group
sudo usermod -aG group-name username

# Remove user from group
sudo gpasswd -d username group-name

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Permissions

File Permissions

Set permissions:

# Set permissions
chmod 755 file

# Set ownership
sudo chown user:group file

Directory Permissions

Set directory permissions:

# Set permissions
chmod 755 directory

# Recursive
chmod -R 755 directory

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‍ User Administration

List Users

List users:

# List users
cat /etc/passwd

# List logged in
who

# List with details
w

User Information

Check user:

# User info
id username

# Groups
groups username

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Troubleshooting

Permission Denied

Fix permissions:

# Check permissions
ls -l file

# Fix ownership
sudo chown user:group file

User Not in Group

Add to group:

# Add to group
sudo usermod -aG group-name username

# Log out and back in

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Summary

This guide covered user and group management for Arch Linux, CachyOS, and other distributions, including creating users, managing groups, and permissions.

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Next Steps

• Security Configuration - Security setup
• System Configuration - System setup
• ArchWiki Users and Groups: https://wiki.archlinux.org/title/Users_and_groups

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This guide covers Arch Linux, CachyOS, and other Linux distributions. For distribution-specific details, refer to your distribution's documentation.