NAME
apm,
zzz —
Advanced
Power Management control program
SYNOPSIS
apm |
[-abdlmSsvz]
[-f
sockname] |
DESCRIPTION
The
apm 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
acpi(4),
apm(4),
apmd(8)
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.