Using the upower command (with examples)

The upower command is a system utility that provides power and battery information and statistics. It can be used to retrieve information about power devices, monitor power status changes, and display version information. In this article, we will explore different use cases of the upower command and provide code examples for each use case.

Use Case 1: Display power and battery information

To display power and battery information, we can use the --dump option with the upower command. This will provide detailed information about the available power devices, their state, and battery statistics.

Code Example:

upower --dump

Motivation:

This use case is useful when you want to quickly check the power and battery information of your system. It can help you determine the current battery status, estimated remaining time, and other relevant details.

Explanation:

• --dump: This option tells the upower command to display detailed power and battery information.

Example Output:

nativepath:          BAT0
  power supply:       yes
  updated:            Wed 01 Dec 2021 09:00:00 PM EET (307 seconds ago)
  has history:        yes
  has statistics:     yes
  battery
    present:          yes
    state:            fully-charged
    warning-level:    none
    energy:           50 Wh
    energy-empty:     0 Wh
    energy-full:      60 Wh
    energy-full-design:60 Wh
    energy-rate:      0 W
    voltage:          12 V
    percentage:       83%
    capacity:         100%
    technology:       lithium-ion

Use Case 2: List all power devices

To list all power devices connected to the system, we can use the --enumerate option with the upower command. This will provide a list of device paths that can be used for further queries or monitoring.

Code Example:

upower --enumerate

Motivation:

This use case is helpful when you want to know the available power devices connected to your system. It can be used to identify specific devices for querying or monitoring purposes.

Explanation:

• --enumerate: This option instructs the upower command to list all power devices.

Example Output:

/org/freedesktop/UPower/devices/line_power_AC
/org/freedesktop/UPower/devices/battery_BAT0

Use Case 3: Watch for and print power status changes

To monitor power status changes and print them in real-time, we can use the --monitor option with the upower command. This will continuously watch for power events and display them on the terminal.

Code Example:

upower --monitor

Motivation:

This use case is valuable when you want to monitor changes in power status on your system. It can help you track power events such as battery level changes, device disconnections, or AC power supply interruptions.

Explanation:

• --monitor: This option enables the upower command to continuously watch for power status changes.

Example Output:

monitor will print power events as they happen

Use Case 4: Watch for and print detailed power status changes

To monitor and print detailed power status changes, including property changes, we can use the --monitor-detail option with the upower command. This will provide more detailed information about power events compared to the regular monitor mode.

Code Example:

upower --monitor-detail

Motivation:

This use case is useful when you need more granular information about power status changes. It can be used for monitoring power events with greater precision and understanding the specific properties that are modified during these events.

Explanation:

• --monitor-detail: This option enables the upower command to monitor and print detailed power status changes.

Example Output:

monitor will print detailed power events as they happen

Use Case 5: Display version

To display the version of the upower command, we can use the --version option. This will provide information about the installed version of the upower utility.

Code Example:

upower --version

Motivation:

This use case is helpful when you want to verify the version of the upower command installed on your system. It can be used to ensure that you are using the latest version or to troubleshoot issues related to specific versions.

Explanation:

• --version: This option instructs the upower command to display the version information.

Example Output:

upower 0.99.11

By using the upower command with different options, we can easily retrieve power and battery information, monitor power status changes, and get version details of the utility. These examples demonstrate the versatility of the upower command and its usefulness in managing power-related aspects of a system.