Linux id Guide

Complete beginner-friendly guide to id on Linux, covering Arch Linux, CachyOS, and other distributions including user identification, group information, and user context.

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Table of Contents

1. Understanding id
2. id Basics
3. User Information
4. Group Information
5. Troubleshooting

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Understanding id

What is id?

id displays user and group IDs.

Uses:

• User ID: Show UID
• Group ID: Show GID
• Groups: List all groups
• User context: Check user information

Why it matters:

• Permissions: Understand user context
• Troubleshooting: Debug permission issues
• Scripts: User-aware automation

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id Basics

Current User

Show your info:

# Show current user info
id

# Output: uid=1000(username) gid=1000(group) groups=1000(group),...

Specific User

Check user:

# Show user info
id username

# Show root
id root

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User Information

User ID Only

Show UID:

# Show UID
id -u

# Show UID of user
id -u username

Username Only

Show username:

# Show username
id -un

# Or
id -u -n

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Group Information

Group ID Only

Show GID:

# Show GID
id -g

# Show GID of user
id -g username

All Groups

List groups:

# Show all groups
id -Gn

# Show group IDs
id -G

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Troubleshooting

id Not Found

Check installation:

# Check id
which id

# Usually in coreutils
# Install if missing
sudo pacman -S coreutils

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Summary

This guide covered id usage, user/group information, and user context for Arch Linux, CachyOS, and other distributions.

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Next Steps

• whoami Guide - Current user
• User and Groups - User management
• id Documentation: man id

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