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>
timer specific configuration options are configured in
the [Timer] section.</para>
- <para>For each timer file a matching unit file must
+ <para>For each timer file, a matching unit file must
exist, describing the unit to activate when the timer
- elapses. By default a service by the same name as the
+ elapses. By default, a service by the same name as the
timer (except for the suffix) is activated. Example: a
timer file <filename>foo.timer</filename> activates a
matching service <filename>foo.service</filename>. The
unit to activate may be controlled by
<varname>Unit=</varname> (see below).</para>
+
+ <para>Unless <varname>DefaultDependencies=</varname>
+ is set to <option>false</option>, timer units will
+ implicitly have dependencies of type
+ <varname>Conflicts=</varname> and
+ <varname>Before=</varname> on
+ <filename>shutdown.target</filename>. These ensure
+ that timer units are stopped cleanly prior to system
+ shutdown. Only timer units involved with early boot or
+ late system shutdown should disable this
+ option.</para>
</refsect1>
<refsect1>
defines. The options specific to the [Timer] section
of timer units are the following:</para>
- <variablelist>
+ <variablelist class='unit-directives'>
<varlistentry>
- <term><varname>OnActive=</varname></term>
- <term><varname>OnBootup=</varname></term>
- <term><varname>OnStartup=</varname></term>
- <term><varname>OnUnitActive=</varname></term>
- <term><varname>OnUnitInactive=</varname></term>
+ <term><varname>OnActiveSec=</varname></term>
+ <term><varname>OnBootSec=</varname></term>
+ <term><varname>OnStartupSec=</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>OnActive=</varname> defines a
+ <varname>OnActiveSec=</varname> defines a
timer relative to the moment the timer
itself is
- activated. <varname>OnBootup=</varname>
+ activated. <varname>OnBootSec=</varname>
defines a timer relative to when the
machine was booted
- up. <varname>OnStartup=</varname>
+ up. <varname>OnStartupSec=</varname>
defines a timer relative to when
- systemd was
- started. <varname>OnUnitActive=</varname>
+ systemd was first
+ started. <varname>OnUnitActiveSec=</varname>
defines a timer relative to when the
unit the timer is activating was last
- activated. <varname>OnUnitInactive=</varname>
+ activated. <varname>OnUnitInactiveSec=</varname>
defines a timer relative to when the
unit the timer is activating was last
deactivated.</para>
<para>Multiple directives may be
- combined, of the same and of different
+ combined of the same and of different
types. For example, by combining
- <varname>OnBoot=</varname> and
- <varname>OnUnitActive=</varname> it is
+ <varname>OnBootSec=</varname> and
+ <varname>OnUnitActiveSec=</varname>, it is
possible to define a timer that
elapses in regular intervals and
activates a specific service each
<para>The arguments to the directives
are time spans configured in
- seconds. Example: "OnBoot=50" means
+ seconds. Example: "OnBootSec=50" means
50s after boot-up. The argument may
also include time units. Example:
- "OnBoot=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>
<para>If a timer configured with
- <varname>OnBootup=</varname> or
- <varname>OnStartup=</varname> is
+ <varname>OnBootSec=</varname> or
+ <varname>OnStartupSec=</varname> is
already in the past when the timer
unit is activated, it will immediately
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,
- independant of wall-clock time and timezones. If the
+ 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
- specified this value defaults to a
+ <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
that the unit name that is activated
and the unit name of the timer unit
- is chosen 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>
~ianmdlvl / elogind.git / blobdiff