This program is used to enter a system sleep state until specified wakeup time.
This uses cross-platform Linux interfaces to enter a system sleep state, and
leave it no later than a specified time. It uses any RTC framework driver that
supports standard driver model wakeup flags.
This is normally used like the old apmsleep utility, to wake from a suspend
state like ACPI S1 (standby) or S3 (suspend-to-RAM). Most platforms can
implement those without analogues of BIOS, APM, or ACPI.
On some systems, this can also be used like nvram-wakeup, waking from states
like ACPI S4 (suspend to disk). Not all systems have persistent media that are
appropriate for such suspend modes.
Options
-v | --verbose
Be verbose.
-h | --help
Display a short help message that shows how to use the program.
-V | --version
Displays version information and exists.
-a | --auto
Reads the clock mode (whether the hardware clock is set to UTC or local time)
from /etc/adjtime. That's the location where the hwclock stores
that information.
-l | --local
Assumes that the hardware clock is set to local time, regardless of the
contents of /etc/adjtime.
-u | --utc
Assumes that the hardware clock is set to UTC (Universal Time Coordinated),
regardless of the contents of /etc/adjtime.
-ddevice | --devicedevice
Uses device instead of rtc0 as realtime clock. This option
is only relevant if your system has more than one RTC. You may specify
rtc1, rtc2, ... here.
-sseconds | --secondsseconds
Sets the wakeup time to seconds in future from now.
-ttime_t | --timetime_t
Sets the wakeup time to the absolute time time_t. time_t
is the time in seconds since 1970-01-01, 00:00 UTC. Use the
date tool to convert between human-readable time and time_t.
-mmode | --modemode
Use standby state mode. Valid values are standby,
mem, disk and on (no suspend). The default is
standby.
HISTORY
The program first appeared as kernel commit message for Linux 2.6 in the GIT
commit 87ac84f42a7a580d0dd72ae31d6a5eb4bfe04c6d.
This is free software. You may redistribute copies of it under the terms
of the GNU General Public License <http://www.gnu.org/licenses/gpl.html>.
There is NO WARRANTY, to the extent permitted by law.
