systemd-ac-power — Report whether we are connected to an external power source
systemd-ac-power may be used to check whether the system
is running on AC power or not. By default it will simply return success (if we
can detect that we are running on AC power) or failure, with no output.
This can be useful for example to debug
The following options are understood:
On success (running on AC power), 0 is returned, a non-zero failure code otherwise.