systemd/man/environment.d.xml
Lennart Poettering 818bf54632 tree-wide: drop 'This file is part of systemd' blurb
This part of the copyright blurb stems from the GPL use recommendations:

https://www.gnu.org/licenses/gpl-howto.en.html

The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.

hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
2018-06-14 10:20:20 +02:00

111 lines
4.3 KiB
XML

<?xml version="1.0"?>
<!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
SPDX-License-Identifier: LGPL-2.1+
Copyright 2016 Red Hat, Inc.
Copyright 2017 Zbigniew Jędrzejewski-Szmek
-->
<refentry id="environment.d" conditional='ENABLE_ENVIRONMENT_D'
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>environment.d</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Ray</firstname>
<surname>Strode</surname>
<email>rstrode@redhat.com</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>environment.d</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>environment.d</refname>
<refpurpose>Definition of user session environment</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>~/.config/environment.d/*.conf</filename></para>
<para><filename>/etc/environment.d/*.conf</filename></para>
<para><filename>/run/environment.d/*.conf</filename></para>
<para><filename>/usr/lib/environment.d/*.conf</filename></para>
<para><filename>/etc/environment</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>The <filename>environment.d</filename> directories contain a list of "global" environment
variable assignments for the user environment.
<citerefentry><refentrytitle>systemd-environment-d-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
parses them and updates the environment exported by the systemd user instance to the services it
starts.</para>
<para>It is recommended to use numerical prefixes for file names to simplify ordering.</para>
<para>For backwards compatibility, a symlink to <filename>/etc/environment</filename> is
installed, so this file is also parsed.</para>
</refsect1>
<xi:include href="standard-conf.xml" xpointer="confd" />
<refsect1>
<title>Configuration Format</title>
<para>The configuration files contain a list of
<literal><replaceable>KEY</replaceable>=<replaceable>VALUE</replaceable></literal> environment
variable assignments, separated by newlines. The right hand side of these assignments may
reference previously defined environment variables, using the <literal>${OTHER_KEY}</literal>
and <literal>$OTHER_KEY</literal> format. It is also possible to use
<literal>${<replaceable>FOO</replaceable>:-<replaceable>DEFAULT_VALUE</replaceable>}</literal>
to expand in the same way as <literal>${<replaceable>FOO</replaceable>}</literal> unless the
expansion would be empty, in which case it expands to <replaceable>DEFAULT_VALUE</replaceable>,
and use
<literal>${<replaceable>FOO</replaceable>:+<replaceable>ALTERNATE_VALUE</replaceable>}</literal>
to expand to <replaceable>ALTERNATE_VALUE</replaceable> as long as
<literal>${<replaceable>FOO</replaceable>}</literal> would have expanded to a non-empty value.
No other elements of shell syntax are supported.</para>
<para>Each <replaceable>KEY</replaceable> must be a valid variable name. Empty lines
and lines beginning with the comment character <literal>#</literal> are ignored.</para>
<refsect2>
<title>Example</title>
<example>
<title>Setup environment to allow access to a program installed in
<filename noindex='true'>/opt/foo</filename></title>
<para><filename>/etc/environment.d/60-foo.conf</filename>:
</para>
<programlisting>
FOO_DEBUG=force-software-gl,log-verbose
PATH=/opt/foo/bin:$PATH
LD_LIBRARY_PATH=/opt/foo/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}
XDG_DATA_DIRS=/opt/foo/share:${XDG_DATA_DIRS:-/usr/local/share/:/usr/share/}
</programlisting>
</example>
</refsect2>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-environment-d-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.environment-generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>