xenial (1) apmsleep.1.gz

Provided by: apmd_3.2.2-15_amd64 bug

NAME

       apmsleep - go into suspend or standby mode and wake-up later

SYNOPSIS

       apmsleep   [-sSnwhVd]  [--suspend]  [--standby]  [--noapm]  [--wait]  [--precise]  [--help]   [--version]
       [--debug] [+]hh:mm

DESCRIPTION

       Some computers, especially laptops, can wake-up from a low-power suspend to DRAM  mode  using  the  Real-
       time-clock  (RTC)  chip.  Apmsleep can be used to set the alarm time in the RTC and to go into suspend or
       standby mode. An interrupt from the RTC causes the computer to wake-up.  The program detects this  event,
       by  waiting  for a leap in the kernel time and terminates successfully. If no time leap occurs within one
       minute, or something goes wrong, the exit value will be non-zero.

       The wake-up time can be specified in two formats:

       +hh:mm specifies a relative offset to the current time. The computer will suspend for  exactly  hh  hours
       and  mm minutes plus a few seconds to wake up.  On some laptops, the timing is not completely accurate so
       it may be a few minutes (or more?) late.

       hh:mm specifies absolute local time in 24-hour format. The time stored in the RTC is not important.   You
       may  change  the  time  zone used, with the TZ environment variable as usual. Daylight saving time is not
       obeyed in this version, but might be in a future release.  WARNING: Do not close cover  of  laptop  after
       suspending the laptop with apmsleep.  Most laptops overheat when running with closed cover.

       Energy  conservation  with  APM  is little for a desktop. Turning of the screen will save 1/2, going into
       standby with drives turned off will save another 1/6th of the current.

       -V, --version
              Print the apmsleep program version and exit immediately.

       -s, --suspend
              Put the machine into suspend mode if possible (default). On my  laptop,  suspend  mode  turns  off
              everything except the memory.

       -S, --standby
              Put  the  machine into standby mode if possible. On my laptop, standby mode turns off screen, hard
              disk, and CPU.

       -w, --wait
              Wait indefinitely for the time leap.

       -p, --precise
              Wait for alarm time to match actual time. Do not wait for time leap.  This might  be  useful  even
              without APM.

       -n, --noapm
              Do  not  call  apm  bios  to  suspend  computer,  just  set the alarm clock and wait for time leap
              indefinitely.

       -d, --debug
              Print some information about what is going on.

REQUIRED SYSTEM CONFIGURATION

       Kernel The special character device /dev/rtc must exist and the kernel needs to be compiled with APM  and
              RTC support.

       BIOS   The  computer  must  have the 'suspend to RAM' feature enabled in the BIOS; 'suspend to Disk' will
              not work, because the computer is turned off completely. You do  not  need  to  enable  the  ALARM
              timer, it will be activated by apmsleep. On some boards, you can configure which interrupts can be
              used to awake from suspend mode. If you have such a board,  you  might  want  to  make  sure  that
              keyboard  (IRQ  1)  and RTC (IRQ 8) are among those interrupts. If your computer does not wake up,
              try to enable 'modem ring' in the BIOS, even if you do not have a modem.

       Privileges
              The program must be run as root or have the SUID attribute set (see chmod(1)).

BUGS

       Apmsleep cannot detect which event terminated the suspension. Possible  events  are:  keyboard  or  mouse
       activity,  modem  ring,  alarm  from  RTC,  any other interrupt. Sometimes, the time leap is not detected
       properly (causing a wrong exit value).

       Should use APM BIOS calls to set alarm clock (not yet supported by kernel).

       This program was tested on a Winbook XL laptop (Pentium) only.  It may not function on your hardware.

AUTHOR

       Written by Peter Englmaier (ppe@mpe.mpg.de) and may be freely distributed under  the  terms  of  the  GNU
       General  Public  License.   The  code  is  based on Paul Gortmacher's RTC test/example program.  There is
       ABSOLUTELY NO WARRANTY for this program.  The current maintainer is Peter Englmaier.

SEE ALSO

       xapm(1), apmd(8).

                                                  January 2004                                       APMSLEEP(1)