NAME
rtcwake - enter a system sleep state until specified wakeup time
SYNOPSIS
rtcwake [options] [-ddevice] [-mstandby_mode] {-sseconds|-ttime_t}
DESCRIPTION
This program is used to enter a system sleep state and to automatically wake from it at a specified 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.
Note that alarm functionality depends on hardware; not every RTC is able to setup an alarm up to 24 hours in the future.
The suspend setup may be interrupted by active hardware; for example wireless USB input devices that continue to send events for some fraction of a second after the return key is pressed. rtcwake tries to avoid this problem and it waits to the terminal to settle down before entering a system sleep.
OPTIONS
-A, --adjfilefile
-a, --auto
--datetimestamp
| YYYYMMDDhhmmss | |
| YYYY-MM-DD hh:mm:ss | |
| YYYY-MM-DD hh:mm | (seconds will be set to 00) |
| YYYY-MM-DD | (time will be set to 00:00:00) |
| hh:mm:ss | (date will be set to today) |
| hh:mm | (date will be set to today, seconds to 00) |
| tomorrow | (time is set to 00:00:00) |
| +5min |
-d, --devicedevice
-l, --local
--list-modes
-m, --modemode
standby
freeze
mem
disk
off
no
on
disable
show
-n, --dry-run
-s, --secondsseconds
-t, --timetime_t
-u, --utc
-v, --verbose
-h, --help
-V, --version
NOTES
Some PC systems can’t currently exit sleep states such as mem using only the kernel code accessed by this driver. They need help from userspace code to make the framebuffer work again.
FILES
/etc/adjtime
HISTORY
The program was posted several times on LKML and other lists before appearing in kernel commit message for Linux 2.6 in the GIT commit 87ac84f42a7a580d0dd72ae31d6a5eb4bfe04c6d.
AUTHORS
The program was written by David Brownell <[email protected]> and improved by Bernhard Walle <[email protected]>.
COPYRIGHT
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.
SEE ALSO
adjtime_config(5), hwclock(8), date(1)
REPORTING BUGS
For bug reports, use the issue tracker <https://github.com/util-linux/util-linux/issues>.
AVAILABILITY
The rtcwake command is part of the util-linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.