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<?xml version='1.0'?> <!--*-nxml-*-->
<?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
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
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(at your option) any later version.
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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 systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="systemd.path">
<refentryinfo>
<title>systemd.path</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>systemd.path</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd.path</refname>
<refpurpose>systemd path configuration files</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>systemd.path</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>A unit configuration file whose name ends in
<filename>.path</filename> encodes information about
a path monitored by systemd, for
path-based activation.</para>
<para>This man page lists the configuration options
specific to this unit type. See
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for the common options of all unit configuration
files. The common configuration items are configured
in the generic [Unit] and [Install] sections. The
path specific configuration options are configured in
the [Path] section.</para>
<para>For each path file, a matching unit file must
exist, describing the unit to activate when the path
changes. By default, a service by the same name as the
path (except for the suffix) is activated. Example: a
path file <filename>foo.path</filename> activates a
matching service <filename>foo.service</filename>. The
unit to activate may be controlled by
<varname>Unit=</varname> (see below).</para>
<para>Internally, path units use the
<citerefentry><refentrytitle>inotify</refentrytitle><manvolnum>7</manvolnum></citerefentry>
API to monitor file systems. Due to that, it suffers by the
same limitations as inotify, and for example cannot be
used to monitor files or directories changed by other
machines on remote NFS file systems.</para>
<para>If an path unit is beneath another mount
point in the file system hierarchy, a dependency
between both units is created automatically.</para>
<para>Unless <varname>DefaultDependencies=</varname>
is set to <option>false</option>, path units will
implicitly have dependencies of type
<varname>Conflicts=</varname> and
<varname>Before=</varname> on
<filename>shutdown.target</filename>. These ensure
that path units are terminated cleanly prior to system
shutdown. Only path units involved with early boot or
late system shutdown should disable this
option.</para>
</refsect1>
<refsect1>
<title>Options</title>
<para>Path files must include a [Path] section,
which carries information about the path(s) it
monitors. The options specific to the [Path] section
of path units are the following:</para>
<variablelist>
<varlistentry>
<term><varname>PathExists=</varname></term>
<term><varname>PathChanged=</varname></term>
<term><varname>DirectoryNotEmpty=</varname></term>
<listitem><para>Defines paths to
monitor for certain changes:
<varname>PathExists=</varname> may be
used to watch the mere existence of a
file or directory. If the file
specified exists the configured unit
is
activated. <varname>PathChanged=</varname>
may be used to watch a file or
directory and activate the configured
unit whenever it changes or is
modified. <varname>DirectoryNotEmpty=</varname>
may be used to watch a directory and
activate the configured unit whenever
it contains at least one file.</para>
<para>The arguments of these
directives must be absolute file
system paths.</para>
<para>Multiple directives may be
combined, of the same and of different
types, to watch multiple paths.</para>
<para>If a path is already existing
(in case of
<varname>PathExists=</varname>) or a
directory already is not empty (in
case of
<varname>DirectoryNotEmpty=</varname>)
at the time the path unit is activated,
then the configured unit is
immediately activated as
well. Something similar does not apply
to <varname>PathChanged=</varname>.
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>Unit=</varname></term>
<listitem><para>The unit to activate
when any of the configured paths
changes. The argument is a unit name,
whose suffix is not
<filename>.path</filename>. If not
specified, this value defaults to a
service that has the same name as the
path unit, except for the suffix. (See
above.) It is recommended that the
unit name that is activated and the
unit name of the path unit are named
identical, except for the
suffix.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<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>inotify</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
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