Copyright 2010 Lennart Poettering
systemd 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
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refnamediv>
<refname>systemd.timer</refname>
- <refpurpose>systemd timer configuration files</refpurpose>
+ <refpurpose>Timer unit configuration</refpurpose>
</refnamediv>
<refsynopsisdiv>
- <para><filename>systemd.timer</filename></para>
+ <para><filename><replaceable>timer</replaceable>.timer</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>A unit configuration file whose name ends in
- <filename>.timer</filename> encodes information about
+ <literal>.timer</literal> encodes information about
a timer controlled and supervised by systemd, for
timer-based activation.</para>
defines. The options specific to the [Timer] section
of timer units are the following:</para>
- <variablelist>
+ <variablelist class='unit-directives'>
<varlistentry>
<term><varname>OnActiveSec=</varname></term>
<term><varname>OnBootSec=</varname></term>
<term><varname>OnUnitActiveSec=</varname></term>
<term><varname>OnUnitInactiveSec=</varname></term>
- <listitem><para>Defines timers
+ <listitem><para>Defines monotonic timers
relative to different starting points:
<varname>OnActiveSec=</varname> defines a
timer relative to the moment the timer
machine was booted
up. <varname>OnStartupSec=</varname>
defines a timer relative to when
- systemd was
+ systemd was first
started. <varname>OnUnitActiveSec=</varname>
defines a timer relative to when the
unit the timer is activating was last
combined of the same and of different
types. For example, by combining
<varname>OnBootSec=</varname> and
- <varname>OnUnitActiveSec=</varname> it is
+ <varname>OnUnitActiveSec=</varname>, it is
possible to define a timer that
elapses in regular intervals and
activates a specific service each
seconds. Example: "OnBootSec=50" means
50s after boot-up. The argument may
also include time units. Example:
- "OnBootSec=5h 30min" means 5 hours and 30
- minutes after boot-up. For details
+ "OnBootSec=5h 30min" means 5 hours and
+ 30 minutes after boot-up. For details
about the syntax of time spans see
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
elapse and the configured unit is
started. This is not the case for
timers defined in the other
- directives.</para></listitem>
+ directives.</para>
<para>These are monotonic timers,
independent of wall-clock time and timezones. If the
computer is temporarily suspended, the
monotonic clock stops too.</para>
+ <para>If the empty string is assigned
+ to any of these options, the list of
+ timers is reset, and all prior
+ assignments will have no
+ effect.</para></listitem>
+
</varlistentry>
+
+ <varlistentry>
+ <term><varname>OnCalendar=</varname></term>
+
+ <listitem><para>Defines realtime
+ (i.e. wallclock) timers via calendar
+ event expressions. See
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for more information on the syntax of
+ calendar event expressions. Otherwise
+ the semantics are similar to
+ <varname>OnActiveSec=</varname> and
+ related settings.</para></listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>Unit=</varname></term>
<listitem><para>The unit to activate
when this timer elapses. The argument is a
unit name, whose suffix is not
- <filename>.timer</filename>. If not
+ <literal>.timer</literal>. If not
specified, this value defaults to a
service that has the same name as the
timer unit, except for the
- suffix. (See above.) It is recommended,
+ suffix. (See above.) It is recommended
that the unit name that is activated
and the unit name of the timer unit
- are named identical, except for the
+ are named identically, except for the
suffix.</para></listitem>
</varlistentry>
</variablelist>
<refsect1>
<title>See Also</title>
<para>
- <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>