.\" Copyright (c) 2007, SUSE LINUX Products GmbH
.\" Bernhard Walle <bwalle@suse.de>
.\"
.\" 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.
.\"
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.\" 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
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.\"
.TH rtcwake 8 "2007-07-13" "" "Linux Programmer's Manual"
.SH NAME
rtcwake - enter a system sleep state until specified wakeup time
.SH SYNOPSIS
\fBrtcwake\fP [-hvVlua] [-d \fIdevice\fP] [-m \fIstandby_mode\fP] -t \fItime_t\fP | -s \fIseconds\fP
.SH DESCRIPTION
This program is used to enter a system sleep state until specified wakeup 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.
.P
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.
.SS Options
.TP
\fB-v\fP | \fB--verbose\fP
Be verbose.
.TP
\fB-h\fP | \fB--help\fP
Display a short help message that shows how to use the program.
.TP
\fB-V\fP | \fB--version\fP
Displays version information and exists.
.TP
\fB-a\fP | \fB--auto\fP
Reads the clock mode (whether the hardware clock is set to UTC or local time)
from \fI/etc/adjtime\fP. That's the location where the \fBhwclock\fP stores
that information.
.TP
\fB-l\fP | \fB--local\fP
Assumes that the hardware clock is set to local time, regardless of the
contents of \fI/etc/adjtime\fP.
.TP
\fB-u\fP | \fB--utc\fP
Assumes that the hardware clock is set to UTC (Universal Time Coordinated),
regardless of the contents of \fI/etc/adjtime\fP.
.TP
\fB-d\fP \fIdevice\fP | \fB--device\fP \fIdevice\fP
Uses \fIdevice\fP instead of \fIrtc0\fP as realtime clock. This option
is only relevant if your system has more than one RTC. You may specify
\fIrtc1\fP, \fIrtc2\fP, ... here.
.TP
\fB-s\fP \fIseconds\fP | \fB--seconds\fP \fIseconds\fP
Sets the wakeup time to \fIseconds\fP in future from now.
.TP
\fB-t\fP \fItime_t\fP | \fB--time\fP \fItime_t\fP
Sets the wakeup time to the absolute time \fItime_t\fP. \fItime_t\fP
is the time in seconds since 1970-01-01, 00:00 UTC. Use the
\fBdate\fP tool to convert between human-readable time and \fItime_t\fP.
.TP
\fB-m\fP \fImode\fP | \fB--mode\fP \fImode\fP
Use standby state \fImode\fP. Valid values are \fIstandby\fP,
\fImem\fP, \fIdisk\fP and \fIon\fP (no suspend). The default is
\fIstandby\fP.
.SH HISTORY
The program first appeared as kernel commit message for Linux 2.6 in the GIT
commit 87ac84f42a7a580d0dd72ae31d6a5eb4bfe04c6d.
.SH AVAILABILITY
The rtcwake command is part of the util-linux-ng package and is available from
ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
.SH AUTHOR
The program was written by David Brownell <david-b@pacbell.net> and improved by
Bernhard Walle <bwalle@suse.de>.
.SH 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.
.SH "SEE ALSO"
.BR hwclock (8),
.BR date (1)
