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APM(8) NetBSD System Manager's Manual APM(8)
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apm, zzz -- Advanced Power Management control program
apm [-abdlmSsvz] [-f sockname]
zzz [-Sz] [-f sockname]
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
Available command-line flags are:
-a Display the external charger (A/C status): 0 means discon-
nected, 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
-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
-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 sys-
tem. 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
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.
/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 spec-
ified; 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.
acpi(4), apm(4), apmd(8)
Intel Corporation and Microsoft Corporation, Advanced Power Management
(APM) BIOS Interface Specification, Revision 1.2, February 1996.
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 per-
sonal computers has relied on ACPI, implemented in NetBSD by the acpi(4)
subsystem. The acpi(4) provides an emulation layer for the legacy apm.
NetBSD 7.1.2 March 20, 2010 NetBSD 7.1.2