.\" Copyright (c) 2007, SUSE LINUX Products GmbH .\" Bernhard Walle .\" .\" This program is free software; you can redistribute it and/or .\" modify it under the terms of the GNU General Public License .\" as published by the Free Software Foundation; either version 2 .\" of the License, or (at your option) any later version. .\" .\" This program is distributed in the hope that it will be useful, .\" but WITHOUT ANY WARRANTY; without even the implied warranty of .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the .\" GNU General Public License for more details. .\" .\" You should have received a copy of the GNU General Public License .\" along with this program; if not, write to the Free Software .\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA .\" 02110-1301, USA. .\" .TH RTCWAKE 8 "June 2015" "util-linux" "System Administration" .SH NAME rtcwake \- enter a system sleep state until specified wakeup time .SH SYNOPSIS .B rtcwake [options] .RB [ \-d .IR device ] .RB [ \-m .IR standby_mode ] .RB { "\-s \fIseconds\fP" | "\-t \fItime_t\fP" } .SH DESCRIPTION This program is used to enter a system sleep state and to automatically wake from it at a specified time. .PP 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. .PP This is normally used like the old \fBapmsleep\fP 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. .PP On some systems, this can also be used like \fBnvram-wakeup\fP, waking from states like ACPI S4 (suspend to disk). Not all systems have persistent media that are appropriate for such suspend modes. .PP Note that alarm functionality depends on hardware; not every RTC is able to setup an alarm up to 24 hours in the future. .PP 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. .B rtcwake tries to avoid this problem and it waits to terminal to settle down before entering a system sleep. .SH OPTIONS .TP .BR \-A , " \-\-adjfile " \fIfile Specify an alternative path to the adjust file. .TP .BR \-a , " \-\-auto" Read the clock mode (whether the hardware clock is set to UTC or local time) from the \fIadjtime\fP file, where .BR hwclock (8) stores that information. This is the default. .TP .BR \-\-date " \fItimestamp" Set the wakeup time to the value of the timestamp. Format of the timestamp can be any of the following: .TS tab(|); l2 l. 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 .TE .TP .BR \-d , " \-\-device " \fIdevice Use the specified \fIdevice\fP instead of \fBrtc0\fP as realtime clock. This option is only relevant if your system has more than one RTC. You may specify \fBrtc1\fP, \fBrtc2\fP, ... here. .TP .BR \-l , " \-\-local" Assume that the hardware clock is set to local time, regardless of the contents of the \fIadjtime\fP file. .TP .B \-\-list\-modes List available \-\-mode option arguments. .TP .BR \-m , " \-\-mode " \fImode Go into the given standby state. Valid values for \fImode\fP are: .RS .TP .B standby ACPI state S1. This state offers minimal, though real, power savings, while providing a very low-latency transition back to a working system. This is the default mode. .TP .B freeze The processes are frozen, all the devices are suspended and all the processors idled. This state is a general state that does not need any platform-specific support, but it saves less power than Suspend-to-RAM, because the system is still in a running state. (Available since Linux 3.9.) .TP .B mem ACPI state S3 (Suspend-to-RAM). This state offers significant power savings as everything in the system is put into a low-power state, except for memory, which is placed in self-refresh mode to retain its contents. .TP .B disk ACPI state S4 (Suspend-to-disk). This state offers the greatest power savings, and can be used even in the absence of low-level platform support for power management. This state operates similarly to Suspend-to-RAM, but includes a final step of writing memory contents to disk. .TP .B off ACPI state S5 (Poweroff). This is done by calling '/sbin/shutdown'. Not officially supported by ACPI, but it usually works. .TP .B no Don't suspend, only set the RTC wakeup time. .TP .B on Don't suspend, but read the RTC device until an alarm time appears. This mode is useful for debugging. .TP .B disable Disable a previously set alarm. .TP .B show Print alarm information in format: "alarm: off|on