What is Complete Guide to lsusb Command in Linux about?

Master the lsusb command in Linux for USB device management, troubleshooting, and system administration with practical examples and options.

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This article is perfect for technology professionals, developers, and anyone interested in system administration looking to enhance their skills and knowledge.

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This article takes approximately 10 minutes to read and contains 1923 words of expert insights and practical information.

What topics are covered?

This article covers key topics including: Command Line, Linux, USB, lsusb, providing comprehensive insights for technology professionals.

Complete Guide to lsusb Command in Linux

Introduction

The lsusb command is a fundamental utility in Linux systems that provides detailed information about Universal Serial Bus (USB) devices connected to your system. This command is part of the usbutils package and serves as the primary tool for diagnosing, troubleshooting, and monitoring USB devices in Linux environments.

USB technology has become ubiquitous in modern computing, with devices ranging from simple storage drives to complex peripherals like printers, cameras, network adapters, and input devices. Understanding how to effectively use lsusb is crucial for system administrators, developers, and power users who need to manage USB connectivity and troubleshoot hardware issues.

Basic Syntax and Usage

The basic syntax of the lsusb command follows this pattern:

`bash lsusb [options] [device_specifier] `

The simplest form of the command requires no arguments:

`bash lsusb `

This basic invocation displays a list of all USB devices currently connected to the system, showing essential information including bus numbers, device addresses, vendor IDs, product IDs, and device descriptions.

Installation and Prerequisites

Most Linux distributions include lsusb by default as part of the usbutils package. However, if it's not installed on your system, you can install it using your distribution's package manager:

Ubuntu/Debian Systems

`bash sudo apt update sudo apt install usbutils `

Red Hat/CentOS/Fedora Systems

`bash

For newer versions using dnf

sudo dnf install usbutils

For older versions using yum

sudo yum install usbutils `

Arch Linux

`bash sudo pacman -S usbutils `

Command Options and Flags

The lsusb command supports numerous options that modify its behavior and output format. Understanding these options is essential for effective USB device management.

| Option | Long Form | Description | |--------|-----------|-------------| | -v | --verbose | Display detailed information about each device | | -s | --bus | Specify bus and device numbers | | -d | --device | Show only devices with specified vendor:product ID | | -D | --device-path | Display information for device at specified path | | -t | --tree | Display devices in tree format showing topology | | -V | --version | Show version information | | -h | --help | Display help message |

Detailed Option Explanations

#### Verbose Output (-v, --verbose) The verbose option provides comprehensive information about USB devices, including configuration descriptors, interface descriptors, and endpoint information. This is particularly useful for developers and system administrators who need detailed technical specifications.

`bash lsusb -v `

#### Bus and Device Selection (-s, --bus) This option allows you to specify particular bus and device combinations to examine specific USB devices. The format follows [[bus]:][devnum] pattern.

`bash lsusb -s 001:002 lsusb -s 001: lsusb -s :002 `

#### Device Filtering (-d, --device) Filter output to show only devices matching specific vendor and product IDs. The format is [vendor]:[product] where IDs are in hexadecimal format.

`bash lsusb -d 1234:5678 lsusb -d 1234: lsusb -d :5678 `

#### Tree Display (-t, --tree) Shows the USB device topology in a hierarchical tree format, displaying how devices are connected through hubs and ports.

`bash lsusb -t `

Understanding lsusb Output

Standard Output Format

When executed without options, lsusb produces output in the following format:

` Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 003: ID 1234:5678 Example Corp. USB Device Name `

Each line represents a connected USB device with the following components:

| Component | Description | Example | |-----------|-------------|---------| | Bus | USB bus number | Bus 001 | | Device | Device number on the bus | Device 003 | | ID | Vendor:Product identification | ID 1234:5678 | | Manufacturer | Device manufacturer name | Example Corp. | | Product | Product description | USB Device Name |

Verbose Output Interpretation

The verbose output provides extensive technical details about each device:

`bash lsusb -v -d 1234:5678 `

This command produces detailed output including:

- Device descriptor information - Configuration descriptors - Interface descriptors - Endpoint descriptors - Device capabilities - Power consumption details - USB version compliance

Practical Examples and Use Cases

Example 1: Basic Device Listing

`bash lsusb `

Output: ` Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:8000 Intel Corp. Bus 001 Device 003: ID 046d:c52b Logitech, Inc. Unifying Receiver Bus 001 Device 004: ID 0781:5567 SanDisk Corp. Cruzer Blade `

Example 2: Tree View Display

`bash lsusb -t `

Output: ` /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/12p, 480M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M |__ Port 9: Dev 3, If 0, Class=Human Interface Device, Driver=usbhid, 12M |__ Port 10: Dev 4, If 0, Class=Mass Storage, Driver=usb-storage, 480M `

Example 3: Detailed Device Information

`bash lsusb -v -s 001:004 `

This command provides comprehensive information about device 004 on bus 001, including technical specifications, power requirements, and supported features.

Example 4: Filtering by Vendor

`bash lsusb -d 046d: `

This shows all devices from Logitech (vendor ID 046d).

Advanced Usage Scenarios

Monitoring USB Device Changes

You can create scripts to monitor USB device connections and disconnections:

`bash #!/bin/bash

USB monitoring script

while true; do clear echo "USB Devices - $(date)" echo "========================" lsusb sleep 2 done `

Identifying Unknown Devices

When troubleshooting unknown USB devices:

`bash

List all devices with detailed information

Checking USB Version Support

To identify USB version capabilities:

`bash lsusb -v | grep -E "bcdUSB|bMaxPacketSize0" `

USB Device Identification and Vendor Codes

Understanding USB vendor and product codes is crucial for device identification. The USB Implementers Forum (USB-IF) assigns unique vendor IDs to manufacturers.

Common Vendor IDs

| Vendor ID | Manufacturer | |-----------|-------------| | 1d6b | Linux Foundation | | 8087 | Intel Corp. | | 046d | Logitech, Inc. | | 0781 | SanDisk Corp. | | 05ac | Apple, Inc. | | 045e | Microsoft Corp. | | 04f2 | Chicony Electronics Co., Ltd | | 0bda | Realtek Semiconductor Corp. |

Device Class Codes

USB devices are categorized by class codes that indicate their functionality:

| Class Code | Description | |------------|-------------| | 00h | Device class defined at interface level | | 01h | Audio | | 02h | Communications and CDC Control | | 03h | Human Interface Device (HID) | | 05h | Physical | | 06h | Image | | 07h | Printer | | 08h | Mass Storage | | 09h | Hub | | 0Ah | CDC Data | | 0Bh | Smart Card | | 0Dh | Content Security | | 0Eh | Video | | 0Fh | Personal Healthcare | | DCh | Diagnostic Device | | E0h | Wireless Controller | | EFh | Miscellaneous | | FEh | Application Specific | | FFh | Vendor Specific |

Troubleshooting with lsusb

Common Issues and Solutions

#### Device Not Recognized

When a USB device isn't recognized:

1. Check if the device appears in lsusb output 2. Verify power requirements 3. Test different USB ports 4. Check for driver issues

`bash

Check if device is detected

lsusb | grep -i "device_name"

Check detailed device information

lsusb -v -d vendor:product `

#### Permission Issues

USB device access may require appropriate permissions:

`bash

Check device permissions

ls -l /dev/bus/usb/001/002

Add user to appropriate groups

sudo usermod -a -G plugdev username `

#### Performance Issues

To diagnose USB performance problems:

`bash

Check USB version and speed

lsusb -v | grep -E "bcdUSB|MaxPower"

Monitor USB tree topology

lsusb -t `

Integration with Other Commands

The lsusb command works effectively with other Linux utilities for comprehensive system analysis.

Combining with grep

`bash

Find specific manufacturers

lsusb | grep "Intel"

Find mass storage devices

lsusb -v | grep -A 10 "Mass Storage" `

Using with dmesg

`bash

Check kernel messages about USB devices

dmesg | grep -i usb

Monitor real-time USB events

dmesg -w | grep -i usb `

Integration with udev

`bash

List udev rules for USB devices

ls /etc/udev/rules.d/usb

Monitor udev events

udevadm monitor --subsystem-match=usb `

Scripting and Automation

Creating USB Inventory Scripts

`bash #!/bin/bash

USB Device Inventory Script

echo "USB Device Inventory Report" echo "Generated on: $(date)" echo "================================"

Count total devices

total_devices=$(lsusb | wc -l) echo "Total USB Devices: $total_devices" echo ""

List devices by manufacturer

echo "Devices by Manufacturer:" lsusb | awk '{print $6, $7, $8, $9}' | sort | uniq -c echo ""

Show USB topology

echo "USB Device Tree:" lsusb -t `

Automated Device Detection

`bash #!/bin/bash

Detect new USB devices

reference_file="/tmp/usb_baseline" current_file="/tmp/usb_current"

Create baseline if it doesn't exist

if [ ! -f "$reference_file" ]; then lsusb > "$reference_file" echo "Baseline created" exit 0 fi

Compare current state with baseline

lsusb > "$current_file" diff "$reference_file" "$current_file" > /dev/null

if [ $? -ne 0 ]; then echo "USB device changes detected:" diff "$reference_file" "$current_file" cp "$current_file" "$reference_file" fi `

Security Considerations

USB Security Monitoring

USB devices can pose security risks, and lsusb helps monitor for unauthorized devices:

`bash

Monitor for unknown devices

lsusb | grep -v -E "(Linux Foundation|Intel Corp|Known_Vendor)"

Check for devices with unusual characteristics

lsusb -v | grep -E "iSerial|iManufacturer" | grep -v -E "known_patterns" `

Device Whitelisting

Create scripts to validate against approved device lists:

`bash #!/bin/bash

USB Device Whitelist Checker

whitelist_file="/etc/usb_whitelist" current_devices=$(lsusb | awk '{print $6}')

for device in $current_devices; do if ! grep -q "$device" "$whitelist_file"; then echo "Unauthorized device detected: $device" # Log to syslog or take appropriate action fi done `

Performance Analysis

USB Bandwidth Monitoring

Understanding USB bandwidth limitations and device requirements:

| USB Version | Maximum Speed | |-------------|---------------| | USB 1.0 | 1.5 Mbps (Low Speed) | | USB 1.1 | 12 Mbps (Full Speed) | | USB 2.0 | 480 Mbps (High Speed) | | USB 3.0 | 5 Gbps (SuperSpeed) | | USB 3.1 | 10 Gbps (SuperSpeed+) | | USB 3.2 | 20 Gbps | | USB4 | 40 Gbps |

Power Consumption Analysis

`bash

Check device power requirements

lsusb -v | grep -E "MaxPower|bMaxPower"

Identify high-power devices

lsusb -v | grep -B 5 -A 5 "MaxPower.*[5-9][0-9][0-9]mA" `

Conclusion

The lsusb command is an indispensable tool for managing USB devices in Linux systems. Its versatility ranges from simple device listing to complex troubleshooting and system analysis. Understanding its various options, output formats, and integration capabilities enables administrators and users to effectively manage USB connectivity, diagnose issues, and maintain system security.

Regular use of lsusb in system administration workflows helps maintain awareness of connected devices, identify potential issues before they become critical problems, and ensure optimal USB subsystem performance. Whether you're troubleshooting a non-functional device, conducting security audits, or developing automated monitoring solutions, lsusb provides the foundation for comprehensive USB device management in Linux environments.

The command's integration with other system utilities and its scriptable nature make it valuable for both interactive troubleshooting and automated system monitoring. As USB technology continues to evolve with new standards and device types, lsusb remains the primary tool for understanding and managing USB connectivity in Linux systems.