Files
systemd/man/sd_path_lookup.xml
Zbigniew Jędrzejewski-Szmek dc04a884e0 systemd-path: add 'system-search-configuration'
This provides functionality to replace what was provided by the preceding
revert:

  $ build/systemd-path system-search-configuration --suffix=sysctl.d
  /etc/sysctl.d:/run/sysctl.d:/usr/local/lib/sysctl.d:/usr/lib/sysctl.d

The result is identical, but more generic, since by changing suffix we can also
get the answer for sysusers.d, tmpfiles.d, and any other of the directories
which follow the same general rule.
2025-11-13 14:11:11 +01:00

238 lines
10 KiB
XML

<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="sd_path_lookup" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_path_lookup</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_path_lookup</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_path_lookup</refname>
<refname>sd_path_lookup_strv</refname>
<refpurpose>Query well-known file system paths</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-path.h&gt;</funcsynopsisinfo>
<!-- note: individual constants are not added as <refname>s, there's just too many -->
<funcsynopsisinfo><token>enum</token> {
<constant>SD_PATH_TEMPORARY</constant>,
<constant>SD_PATH_TEMPORARY_LARGE</constant>,
<constant>SD_PATH_SYSTEM_BINARIES</constant>,
<constant>SD_PATH_SYSTEM_INCLUDE</constant>,
<constant>SD_PATH_SYSTEM_LIBRARY_PRIVATE</constant>,
<constant>SD_PATH_SYSTEM_LIBRARY_ARCH</constant>,
<constant>SD_PATH_SYSTEM_SHARED</constant>,
<constant>SD_PATH_SYSTEM_CONFIGURATION_FACTORY</constant>,
<constant>SD_PATH_SYSTEM_STATE_FACTORY</constant>,
<constant>SD_PATH_SYSTEM_CONFIGURATION</constant>,
<constant>SD_PATH_SYSTEM_SEARCH_CONFIGURATION</constant>,
<constant>SD_PATH_SYSTEM_RUNTIME</constant>,
<constant>SD_PATH_SYSTEM_RUNTIME_LOGS</constant>,
<constant>SD_PATH_SYSTEM_STATE_PRIVATE</constant>,
<constant>SD_PATH_SYSTEM_STATE_LOGS</constant>,
<constant>SD_PATH_SYSTEM_STATE_CACHE</constant>,
<constant>SD_PATH_SYSTEM_STATE_SPOOL</constant>,
<constant>SD_PATH_USER_BINARIES</constant>,
<constant>SD_PATH_USER_LIBRARY_PRIVATE</constant>,
<constant>SD_PATH_USER_LIBRARY_ARCH</constant>,
<constant>SD_PATH_USER_SHARED</constant>,
<constant>SD_PATH_USER_CONFIGURATION</constant>,
<constant>SD_PATH_USER_RUNTIME</constant>,
<constant>SD_PATH_USER_STATE_PRIVATE</constant>,
<constant>SD_PATH_USER_STATE_CACHE</constant>,
<constant>SD_PATH_USER</constant>,
<constant>SD_PATH_USER_DOCUMENTS</constant>,
<constant>SD_PATH_USER_MUSIC</constant>,
<constant>SD_PATH_USER_PICTURES</constant>,
<constant>SD_PATH_USER_VIDEOS</constant>,
<constant>SD_PATH_USER_DOWNLOAD</constant>,
<constant>SD_PATH_USER_PUBLIC</constant>,
<constant>SD_PATH_USER_TEMPLATES</constant>,
<constant>SD_PATH_USER_DESKTOP</constant>,
<constant>SD_PATH_SEARCH_BINARIES</constant>,
<constant>SD_PATH_SEARCH_BINARIES_DEFAULT</constant>,
<constant>SD_PATH_SEARCH_LIBRARY_PRIVATE</constant>,
<constant>SD_PATH_SEARCH_LIBRARY_ARCH</constant>,
<constant>SD_PATH_SEARCH_SHARED</constant>,
<constant>SD_PATH_SEARCH_CONFIGURATION_FACTORY</constant>,
<constant>SD_PATH_SEARCH_STATE_FACTORY</constant>,
<constant>SD_PATH_SEARCH_CONFIGURATION</constant>,
<constant>SD_PATH_SYSTEMD_UTIL</constant>,
<constant>SD_PATH_SYSTEMD_SYSTEM_UNIT</constant>,
<constant>SD_PATH_SYSTEMD_SYSTEM_PRESET</constant>,
<constant>SD_PATH_SYSTEMD_USER_UNIT</constant>,
<constant>SD_PATH_SYSTEMD_USER_PRESET</constant>,
<constant>SD_PATH_SYSTEMD_SYSTEM_CONF</constant>,
<constant>SD_PATH_SYSTEMD_USER_CONF</constant>,
<constant>SD_PATH_SYSTEMD_SEARCH_SYSTEM_UNIT</constant>,
<constant>SD_PATH_SYSTEMD_SEARCH_USER_UNIT</constant>,
<constant>SD_PATH_SYSTEMD_SYSTEM_GENERATOR</constant>,
<constant>SD_PATH_SYSTEMD_USER_GENERATOR</constant>,
<constant>SD_PATH_SYSTEMD_SEARCH_SYSTEM_GENERATOR</constant>,
<constant>SD_PATH_SYSTEMD_SEARCH_USER_GENERATOR</constant>,
<constant>SD_PATH_SYSTEMD_SLEEP</constant>,
<constant>SD_PATH_SYSTEMD_SHUTDOWN</constant>,
<constant>SD_PATH_TMPFILES</constant>,
<constant>SD_PATH_SYSUSERS</constant>,
<constant>SD_PATH_SYSCTL</constant>,
<constant>SD_PATH_BINFMT</constant>,
<constant>SD_PATH_MODULES_LOAD</constant>,
<constant>SD_PATH_CATALOG</constant>,
<constant>SD_PATH_SYSTEMD_SEARCH_NETWORK</constant>,
<constant>SD_PATH_SYSTEMD_SYSTEM_ENVIRONMENT_GENERATOR</constant>,
<constant>SD_PATH_SYSTEMD_USER_ENVIRONMENT_GENERATOR</constant>,
<constant>SD_PATH_SYSTEMD_SEARCH_SYSTEM_ENVIRONMENT_GENERATOR</constant>,
<constant>SD_PATH_SYSTEMD_SEARCH_USER_ENVIRONMENT_GENERATOR</constant>,
};</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_path_lookup</function></funcdef>
<paramdef>uint64_t <parameter>type</parameter></paramdef>
<paramdef>const char *<parameter>suffix</parameter></paramdef>
<paramdef>char **<parameter>paths</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_path_lookup_strv</function></funcdef>
<paramdef>uint64_t <parameter>type</parameter></paramdef>
<paramdef>const char *<parameter>suffix</parameter></paramdef>
<paramdef>char ***<parameter>paths</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_path_lookup()</function> and <function>sd_bus_path_lookup_strv()</function> return a
single path or set of file system paths specified by the argument <parameter>type</parameter>. In case of
<function>sd_path_lookup()</function> a single <constant>NUL</constant>-terminated string is returned.
When <parameter>type</parameter> specifies a set of paths, they are concatenated using
<literal>:</literal> as a separator (as is traditionally done for e.g. <varname>$PATH</varname> or
<varname>$LD_LIBRARY_PATH</varname>). In case of <function>sd_path_lookup_strv()</function> a
<constant>NULL</constant>-terminated array of strings is returned (strv). If suffix
<parameter>suffix</parameter> is given, it is concatenated to each of the paths after a slash
(<literal>/</literal>). All returned paths are absolute.</para>
<para>For paths which refer to user directories, the relevant XDG standard is followed, with support for
environment variables like <varname>$XDG_DOCUMENTS_DIR</varname>, <varname>$XDG_DESKTOP_DIR</varname>,
..., and explicit configuration in <filename>/etc/xdg/user-dirs.conf</filename> or
<filename>${XDG_CONFIG_HOME}/user-dirs.dirs</filename>. See
<ulink url="https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html">
XDG Base Directory Specification</ulink> for details.</para>
<para><citerefentry><refentrytitle>systemd-path</refentrytitle><manvolnum>1</manvolnum></citerefentry> is
a wrapper around <function>sd_path_lookup()</function> and allows the same set of paths to be queried.
</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, <function>sd_path_lookup()</function> and <function>sd_path_lookup_strv()</function>
return a non-negative integer. On failure, a negative errno-style error number is returned by either
function.</para>
<para>The returned string or string array (strv) must be
<citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>'d by the
caller.</para>
<refsect2 id='errors'>
<title>Errors</title>
<para>Returned errors may indicate the following problems:</para>
<variablelist>
<varlistentry>
<term><constant>-EOPNOTSUPP</constant></term>
<listitem><para>Unknown identifier <parameter>type</parameter>.</para>
<xi:include href="version-info.xml" xpointer="v246"/></listitem>
</varlistentry>
<varlistentry>
<term><constant>-EINVAL</constant></term>
<listitem><para>Output argument is <constant>NULL</constant>.</para>
<xi:include href="version-info.xml" xpointer="v246"/></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENXIO</constant></term>
<listitem><para>Query failed because of an undefined environment variable (e.g. for
<constant>SD_PATH_USER_RUNTIME</constant> when <varname>$XDG_RUNTIME_DIR</varname> is not
defined).</para>
<xi:include href="version-info.xml" xpointer="v246"/></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ENOMEM</constant></term>
<listitem><para>Memory allocation failed.</para>
<xi:include href="version-info.xml" xpointer="v246"/></listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>
<refsect1>
<title>Examples</title>
<refsect2>
<title>Look up the location of ~/Documents</title>
<programlisting><xi:include href="path-documents.c" parse="text" /></programlisting>
<para>Note that the default answer of <filename index='false'>$HOME/Documents</filename> may be
overridden by <filename index='false'>user-dirs.conf</filename> or
<varname>$XDG_DOCUMENTS_DIR</varname>.</para>
</refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<refsect1>
<title>History</title>
<para><function>sd_path_lookup()</function> and
<function>sd_path_lookup_strv()</function> were added in version 246.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para><simplelist type="inline">
<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>sd-path</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>systemd-path</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
</simplelist></para>
</refsect1>
</refentry>