DOKK / manpages / debian 12 / powermgmt-base / on_ac_power.1.en
ON_AC_POWER(1) General Commands Manual ON_AC_POWER(1)

on_ac_power - test whether computer is running on AC power

on_ac_power

on_ac_power checks whether the system is running on abundant power (such as AC mains, an USB charger, etc), as opposed to battery power.

None.

0 (true)	System is on mains power
1 (false)	System is not on mains power
255 (false)	Power status could not be determined

The vast majority of desktops and servers have no power sensors, thus they return 255 "unknown"; for most purposes you'd want to consider this answer to imply mains power — note that 255 evaluates as false for the shell.

This program currently provides only information known to the kernel; it doesn't (yet?) query userspace daemons such as nut which may provide further information.

This manual page was written by Steve Dodd <steved@loth.demon.co.uk>, was updated by Thomas Hood then by Adam Borowski.

12 March 2018