pm-is-supported

pm-is-supported

The `pm-is-supported` command is a utility used to determine if the system supports power management features like suspend and hibernate. It primarily checks for the presence of necessary kernel features and hardware capabilities to ensure these functions can operate correctly. The tool examines different power management implementations, including the traditional APM (Advanced Power Management), ACPI (Advanced Configuration and Power Interface), and newer standards. If the command executes without error, it typically indicates that power management is at least partially supported. However, successful execution doesn't guarantee flawless operation, as specific hardware configurations can still present issues. The output, or lack thereof, is the primary indicator. When the command returns without any printed output, then it is considered supported. `pm-is-supported` is often used in scripts or during system initialization to configure power-saving settings and ensure appropriate behavior when the system enters low-power states. Problems can be further investigated using `dmesg`.

The absence of an error code does not guarantee that suspend or hibernate will work flawlessly. Specific hardware or driver issues may still prevent successful power management.

The command returns 0 if power management is supported, and a non-zero value if it is not. In most scenarios no output is provided to standard out or standard error unless it fails.

If suspend or hibernate fails even after `pm-is-supported` indicates support, check system logs (e.g., `/var/log/syslog`, `/var/log/kern.log`) for error messages related to power management or specific device drivers.

The `pm-is-supported` command is part of the `pm-utils` package, which was developed to provide a standardized way to manage power management events on Linux systems. It's been a common tool for detecting power management capabilities across various distributions. The `pm-utils` package aimed to simplify power management scripting and configuration, replacing earlier, more fragmented approaches.

pm-suspend(1), pm-hibernate(1), pm-powersave(8), systemctl(1)