POWERD(8) BSD System Manager's Manual POWERD(8)
powerd -- power management daemon for sysmon
powerd acts upon power management events posted by the kernel's power
management facility. When events are posted, powerd translates the event
into a script name and a list of arguments. powerd then runs the script
in order to implement the power management policy defined by the system
powerd supports the following options:
-d Enable debugging mode. Verbose messages will be sent to stderr and
powerd will stay in the foreground of the controlling terminal.
All of powerd's configuration is encapsulated into scripts that are run
when power management events occur. powerd will look for these scripts
in two locations. The first location is
/etc/powerd/scripts/<power_type>, where <power_type> is defined by the
power management mechanism supported by the system, e.g., ``apm'' or
``acpi''. If the script is not found in the first location, powerd looks
Configuration scripts are run synchronously, i.e., powerd will start the
script and wait for its completion before it handles the next event.
Configuration scripts are called with different arguments, depending on
the script class. These classes are described in the following sections.
POWER SWITCH SCRIPTS
Power switch scripts are called when a state change event occurs on a
power switch device. Power switch scripts are called with two arguments:
the device with which the device is associated, and the event type.
The following power switch script names are defined:
power_button This script is called when an event occurs on a power but-
reset_button This script is called when an event occurs on a reset but-
sleep_button This script is called when an event occurs on a sleep but-
lid_switch This script is called when an event occurs on a lid switch
The following events are defined for power switch devices:
pressed The button was pressed or the lid closed.
released The button was released or the lid opened. Note that power and
sleep button devices usually do not post this type of event.
The following is an example of how a power button script might be invoked
when a power button is pressed by the operator:
/etc/powerd/scripts/power_button acpi0 pressed
acpi(4), acpibut(4), acpilid(4), apm(4)
powerd first appeared in NetBSD 2.0.
powerd was written by Jason R. Thorpe <thorpejATwasabisystems.com> and
contributed by Wasabi Systems, Inc.
Due to its synchronous nature powerd cannot be trusted to handle events
within a certain time.
BSD April 25, 2004 BSD