Provided by: apmd_3.2.2-14build1_amd64 bug

NAME

       apmd - Advanced Power Management (APM) daemon

SYNOPSIS

       apmd [ -TVWciqv ] [ -P program ] [ -T seconds ] [ -c seconds ] [ -p percent ] [ -v level ]
       [ -w percent ]

DESCRIPTION

       apmd is an monitoring daemon for the Advanced Power Management (APM) subsystem.   The  APM
       subsystem  consists  of power-management hardware, firmware usually referred to as the APM
       BIOS and a driver in the operating system  kernel.   The  daemon  can  execute  a  program
       (usually  a shell script) when events are reported by the APM subsystem, and will log, via
       syslogd(8), certain changes in power status.  When the  available  battery  power  becomes
       very low it can alert the user.

       When  the  APM subsystem notifies the daemon of a pending suspend or standby request, apmd
       will run a proxy program, log the event, sync(2) data to the disk and then  tell  the  APM
       subsystem to continue its operation.

       Preparations  for  power  management events are made mainly by the proxy program specified
       using the -P option.  The proxy program is invoked with one or two arguments:

       start  Invoked when the daemon starts.

       stop   Invoked when the daemon stops.

       standby ( system | user )
              Invoked when the APM subsystem reports that standby has been initiated.  The second
              parameter  indicates  whether  firmware  ("system")  or  software  ("user") was the
              originator of the event.

              The "standby" mode conserves power but leaves the machine able  to  respond  almost
              immediately  to  user activity.  Most laptops can't stay in standby mode on battery
              power for more than a few hours or a day.  Normally, nothing special  needs  to  be
              done to prepare for "standing by".

       suspend ( system | user )
              Invoked  when  the  APM  subsystem reports that suspension has been initiated.  The
              second parameter indicates whether firmware ("system") or software ("user") was the
              originator of the event.

              The  "suspend"  mode  aggressively conserves power.  Usually this involves shutting
              off power to all devices except the CPU core and memory, which are put into a  very
              low  power  mode.   Most laptops can stay suspended, using battery power alone, for
              several days.  ("Hibernation" is a kind of super-suspend, where all that  state  is
              written  to  disk  and  the  machine  uses  no  power.  Hibernation is treated like
              suspension by the APM subsystem.)

              Before suspending, PCMCIA devices may need to be  disabled  using  cardctl(8),  and
              some  modular device drivers may need to be unloaded if they have not been designed
              to support power management.

       resume ( suspend | standby | critical )
              Invoked when the APM subsystem reports that computer has resumed normal  operation.
              The second parameter indicates the kind of event from which the system is resuming.
              (A "critical" suspend is a  suspension  that  the  APM  subsystem  performs  in  an
              emergency.   Some  kernels  do not pass this event to user space.  If apmd receives
              the event, it acknowledges the event  and  exits  immediately  without  logging  or
              running the proxy program.)

              When  resuming, PCMCIA devices may need to be re-enabled using cardctl(8), and some
              modular drivers may need to be reloaded.  Note that  in  the  case  of  a  critical
              suspend, the system state may not have been completely saved.

       change power
              Invoked  when  the APM subsystem reports a change in power status, such as a switch
              from mains to battery power.

       change battery
              Invoked when the APM subsystem reports that the charge of one or more batteries  is
              low.  A few minutes of battery power may remain.

       change capability
              Invoked   when   the   APM  subsystem  reports  some  change  in  power  management
              capabilities.  It may have been caused by operation of a setup utility, or  by  the
              installation or removal of devices.

       apmd  emits  various  messages,  most  of  which are self-explanatory.  Battery status log
       entries contain three fields, separated by commas.  The first field indicates how full the
       battery  is  as  a  percentage  of  its  capacity.  The second field indicates whether the
       battery  is  charging,  not  charging,  or  discharging.   When  possible,  apmd  adds  in
       parentheses  its  estimate  of  the  rate  of  charging  or  discharging.  The third field
       indicates how much time the battery can or could be used  to  power  the  computer.   This
       information is provided by the APM subsystem.  When possible, apmd adds in parentheses its
       own estimate of the battery life (if discharging) or of the time required  to  charge  the
       battery fully (if charging).

OPTIONS

       -P program, --proxy program
              Specifies  the  proxy  program  to execute when events are received.  See above for
              information about the arguments supplied to this program.

       -T [seconds] , --proxy-timeout [seconds]
              Sets a time-out for the proxy.  Without this option (or  with  this  option  and  a
              negative  argument)  apmd waits indefinitely for the proxy to finish.  If the proxy
              enters an infinite loop or wait then the machine may appear to  have  crashed.   If
              this option is given a positive integer argument then apmd will wait only that many
              seconds for the proxy to finish, after which it will log a warning, kill the proxy,
              and continue processing the event.  The default is 30 seconds.

       -V, --version
              Prints the version of the apmd program.

       -W, --wall
              In  addition to logging low battery status (as determined either by the -w level or
              by the firmware) using syslog(2), apmd will, given this option, also use wall(1) to
              alert  all  users.   This is most useful if syslogd(8) is not set up to write ALERT
              messages to all users.  If both methods are used, more warnings will be made during
              the critical time period.

       -c [seconds] , --check [seconds]
              Controls  how many seconds to wait for an event.  Without this option (or with this
              option and a negative argument) apmd waits indefinitely  for  an  event.   If  this
              option  is  given  a  positive  integer argument then apmd will wait only that many
              seconds before checking the battery level  and  possibly  sending  out  a  warning,
              calling the proxy or making an entry in the log.  The default is 30 seconds.

       -i, --ignore-bios-battery-low
              Causes  apmd  to  ignore  a  LOW  BATTERY  signal  sent by the APM subsystem.  Some
              firmware signals a low battery at the wrong time.  Note that LOW BATTERY events may
              still be generated by apmd itself based on the warning level.

       -p percent, --percentage percent
              Controls  how  often the battery status is logged.  A new line is printed each time
              the battery content changes by percent_change if logging is enabled.   The  default
              is  5.   Use  a  value  greater than 100 to disable periodic logging of the battery
              level.

       -q, --quiet-bios-battery-low
              Causes apmd not to generate a warning when a LOW BATTERY signal  is  received  from
              the  APM subsystem.  The firmware on some machines produces an audible warning when
              power is about to be used up, so an extra warning may not be needed.

       -v [level] , --verbose [level]
              The daemon can generate messages of varying degrees of unimportance.  Each  message
              is  assigned  one  of  the  priority  levels  defined for the syslogd(8) subsystem,
              ranging from 0 (EMERG, least unimportant) to 7  (DEBUG,  most  unimportant).   This
              option  sets  the  threshold level above which messages are suppressed.  Without an
              argument it increments the threshold by 1, thus  making  apmd  more  verbose.   The
              default is 5 (NOTICE).

       -w percent, --warn percent
              When  the  battery  is  not  being  charged and the battery content falls below the
              specified percent of capacity, and no such event has yet occurred  in  the  current
              discharge  cycle,  apmd  will log a warning at the ALERT log level to syslog(2) and
              generate a LOW BATTERY event.  If the -W or --wall option  was  given,  the  daemon
              will  also  use  wall(1) to alert all users of impending doom.  The default warning
              level is 10.  Use a negative value to disable this feature.

       -h, --help
              Causes apmd to print a brief command summary and exit.

BUGS

       This daemon supports all APM events described in the APM BIOS specification  version  1.2;
       however  it  fails  to support some of the advanced features of APM 1.2, such as reporting
       the conditions of multiple batteries.  (Multiple batteries are  currently  treated  as  if
       they were just one large one.)

       Estimates of charge and discharge rates and times can be very inaccurate.

       There is no interaction yet with ACPI support as found in newer PC hardware.

FILES

       /dev/apm_bios
              Device through which apmd communicates with the Linux APM driver.

       /proc/apm
              APM driver status information

       /etc/apmd_proxy
              Proxy program that is run if none is specified.

       /etc/apm/apmd_proxy
              Proxy program that is run if none is specified. (Debian)

AUTHOR

       This  program  was  written  by Rik Faith (faith@cs.unc.edu) and may be freely distributed
       under the terms of the GNU General Public License.  There is ABSOLUTELY  NO  WARRANTY  for
       this program.  The current maintainer is Avery Pennarun (apenwarr@worldvisions.ca).

SEE ALSO

       apm(1), xapm(1), cardctl(8), syslogd(8).

                                           January 2004                                   APMD(8)