<?xml version='1.0'?>
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!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">
<para>Each file is a plain text file divided into sections, with configuration entries in the
style <replaceable>key</replaceable>=<replaceable>value</replaceable>.
- Empty lines and lines starting with <literal>#</literal> or <literal>;</literal> are
+ 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.</para>
+ 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
Setting="something" "some thing" "…"
KeyTwo=value 2 \
value 2 continued
+
+[Section C]
+KeyThree=value 2\
+# this line is ignored
+; this line is ignored too
+ value 2 continued
</programlisting></example>
<para>Boolean arguments used in configuration files can be written in