mirror of
https://github.com/systemd/systemd
synced 2024-11-05 18:25:39 +00:00
139 lines
7.1 KiB
XML
139 lines
7.1 KiB
XML
<?xml version='1.0'?>
|
||
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
||
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
|
||
<!ENTITY % entities SYSTEM "custom-entities.ent" >
|
||
%entities;
|
||
]>
|
||
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
|
||
|
||
<refentry id="systemd.syntax">
|
||
|
||
<refentryinfo>
|
||
<title>systemd.syntax</title>
|
||
<productname>systemd</productname>
|
||
</refentryinfo>
|
||
|
||
<refmeta>
|
||
<refentrytitle>systemd.syntax</refentrytitle>
|
||
<manvolnum>7</manvolnum>
|
||
</refmeta>
|
||
|
||
<refnamediv>
|
||
<refname>systemd.syntax</refname>
|
||
<refpurpose>General syntax of systemd configuration files</refpurpose>
|
||
</refnamediv>
|
||
|
||
<refsect1>
|
||
<title>Introduction</title>
|
||
|
||
<para>This page describes the basic principles of configuration files used by
|
||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
and related programs for:
|
||
<itemizedlist>
|
||
<listitem><para>systemd unit files, see
|
||
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.nspawn</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||
</para></listitem>
|
||
|
||
<listitem><para>link files, see
|
||
<citerefentry><refentrytitle>systemd.link</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||
</para></listitem>
|
||
|
||
<listitem><para>netdev and network files, see
|
||
<citerefentry><refentrytitle>systemd.netdev</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||
</para></listitem>
|
||
|
||
<listitem><para>daemon config files, see
|
||
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd-user.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>logind.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>journal-remote.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>journal-upload.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd-sleep.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>timesyncd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
||
</para></listitem>
|
||
</itemizedlist>
|
||
</para>
|
||
|
||
<para>The syntax is inspired by
|
||
<ulink url="http://standards.freedesktop.org/desktop-entry-spec/latest/">XDG Desktop Entry Specification</ulink>
|
||
<filename>.desktop</filename> files, which are in turn inspired by Microsoft Windows
|
||
<filename>.ini</filename> files.
|
||
</para>
|
||
|
||
<para>Each file is a plain text file divided into sections, with configuration entries in the
|
||
style <replaceable>key</replaceable>=<replaceable>value</replaceable>.
|
||
Whitespace immediately before or after the <literal>=</literal> is ignored. Empty lines and lines starting with <literal>#</literal> or <literal>;</literal> are
|
||
ignored, which may be used for commenting.</para>
|
||
|
||
<para>Lines ending in a backslash are concatenated with the following line while reading and the
|
||
backslash is replaced by a space character. This may be used to wrap long lines. The limit on
|
||
line length is very large (currently 1 MB), but it is recommended to avoid such long lines and
|
||
use multiple directives, variable substitution, or other mechanism as appropriate for the given
|
||
file type. When a comment line or lines follow a line ending with a backslash, the comment block
|
||
is ignored, so the continued line is concatenated with whatever follows the comment block.</para>
|
||
|
||
<example><programlisting>[Section A]
|
||
KeyOne=value 1
|
||
KeyTwo=value 2
|
||
|
||
# a comment
|
||
|
||
[Section B]
|
||
Setting="something" "some thing" "…"
|
||
KeyTwo=value 2 \
|
||
value 2 continued
|
||
|
||
[Section C]
|
||
KeyThree=value 3\
|
||
# this line is ignored
|
||
; this line is ignored too
|
||
value 3 continued
|
||
</programlisting></example>
|
||
|
||
<para>Boolean arguments used in configuration files can be written in
|
||
various formats. For positive settings the strings
|
||
<option>1</option>, <option>yes</option>, <option>true</option>
|
||
and <option>on</option> are equivalent. For negative settings, the
|
||
strings <option>0</option>, <option>no</option>,
|
||
<option>false</option> and <option>off</option> are
|
||
equivalent.</para>
|
||
|
||
<para>Time span values encoded in configuration files can be written in various formats. A stand-alone
|
||
number specifies a time in seconds. If suffixed with a time unit, the unit is honored. A
|
||
concatenation of multiple values with units is supported, in which case the values are added
|
||
up. Example: <literal>50</literal> refers to 50 seconds; <literal>2min 200ms</literal> refers to
|
||
2 minutes and 200 milliseconds, i.e. 120200 ms. The following time units are understood:
|
||
<literal>s</literal>, <literal>min</literal>, <literal>h</literal>, <literal>d</literal>,
|
||
<literal>w</literal>, <literal>ms</literal>, <literal>us</literal>. For details see
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
|
||
|
||
<para>Various settings are allowed to be specified more than once, in which case the
|
||
interpretation depends on the setting. Often, multiple settings form a list, and setting to an
|
||
empty value "resets", which means that previous assignments are ignored. When this is allowed,
|
||
it is mentioned in the description of the setting. Note that using multiple assignments to the
|
||
same value makes the file incompatible with parsers for the XDG <filename>.desktop</filename>
|
||
file format.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See Also</title>
|
||
<para>
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
||
</para>
|
||
</refsect1>
|
||
|
||
</refentry>
|