NAME
apm
, zzz
—
Advanced Power Management control
program
SYNOPSIS
apm |
[-abdlmSsvz ] [-f
sockname] |
zzz |
[-Sz ] [-f
sockname] |
DESCRIPTION
Theapm
program communicates with the Advanced Power
Management (APM) daemon,
apmd(8), making requests of the current power status or placing the
system either into suspend or stand-by state. The apm
tool is only installed on supported platforms.
With no flags, apm
displays the current
power management state in verbose form.
Available command-line flags are:
-a
- Display the external charger (A/C status): 0 means disconnected, 1 means connected, 2 means backup power source, and 255 means unknown.
-b
- Display the battery status: 0 means high, 1 means low, 2 means critical, 3 means charging, 4 means absent, and 255 means unknown.
-d
- Do not communicate with the APM daemon; attempt instead to manipulate the APM control device directly.
-f
sockname- Set the name of the socket via which to contact apmd(8) to sockname.
-l
- Display the estimated battery lifetime in percent.
-m
- Display the estimated battery lifetime in minutes.
-S
- Put the system into stand-by (light sleep) mode.
-s
- Display if power management is enabled.
-v
- Request more verbose description of the displayed states.
-z
- Put the system into suspend (deep sleep) mode.
The zzz
variant of this command is an
alternative for suspending the system. With no arguments,
zzz
places the system into suspend mode. The command
line flags serve the same purpose as for the apm
variant of this command.
This command does not wait for positive confirmation that the requested mode has been entered; to do so would mean the command does not return until the system resumes from its sleep state.
FILES
/var/run/apmdev is the default UNIX-domain
socket used for communication with
apmd(8). The -f
flag may be used to specify
an alternate socket name. The protection modes on this socket govern which
users may access the APM functions.
/dev/apmctl is the control device which is
used when the -d
flag is specified; it must be
writable for the -d
flag to work successfully.
/dev/apm is the status device used when the socket
is not accessible; it must be readable to provide current APM status.
SEE ALSO
Intel Corporation and Microsoft Corporation, Advanced Power Management (APM) BIOS Interface Specification, Revision 1.2, February 1996.
HISTORY
The apm
command appeared in
NetBSD 1.3.
The APM specification first appeared in 1992. The last update to
the standard was made in 1996 - the same year when it was superceded by the
ACPI 1.0 standard. Thereafter power management on IBM-compatible personal
computers has relied on ACPI, implemented in NetBSD
by the acpi(4) subsystem. The
acpi(4) provides an emulation layer for the legacy
apm
.