man/sd_path_lookup.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="sd_path_lookup" xmlns:xi="http://www.w3.org/2001/XInclude">
   7
   8   <refentryinfo>
   9     <title>sd_path_lookup</title>
  10     <productname>systemd</productname>
  11   </refentryinfo>
  12
  13   <refmeta>
  14     <refentrytitle>sd_path_lookup</refentrytitle>
  15     <manvolnum>3</manvolnum>
  16   </refmeta>
  17
  18   <refnamediv>
  19     <refname>sd_path_lookup</refname>
  20     <refname>sd_path_lookup_strv</refname>
  21
  22     <refpurpose>Query well-known file system paths</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <funcsynopsis>
  27       <funcsynopsisinfo>#include &lt;systemd/sd-path.h&gt;</funcsynopsisinfo>
  28
  29       <!-- note: individual constants are not added as <refname>s, there's just too many -->
  30
  31       <funcsynopsisinfo><token>enum</token> {
  32         <constant>SD_PATH_TEMPORARY</constant>,
  33         <constant>SD_PATH_TEMPORARY_LARGE</constant>,
  34
  35         <constant>SD_PATH_SYSTEM_BINARIES</constant>,
  36         <constant>SD_PATH_SYSTEM_INCLUDE</constant>,
  37         <constant>SD_PATH_SYSTEM_LIBRARY_PRIVATE</constant>,
  38         <constant>SD_PATH_SYSTEM_LIBRARY_ARCH</constant>,
  39         <constant>SD_PATH_SYSTEM_SHARED</constant>,
  40         <constant>SD_PATH_SYSTEM_CONFIGURATION_FACTORY</constant>,
  41         <constant>SD_PATH_SYSTEM_STATE_FACTORY</constant>,
  42
  43         <constant>SD_PATH_SYSTEM_CONFIGURATION</constant>,
  44         <constant>SD_PATH_SYSTEM_RUNTIME</constant>,
  45         <constant>SD_PATH_SYSTEM_RUNTIME_LOGS</constant>,
  46         <constant>SD_PATH_SYSTEM_STATE_PRIVATE</constant>,
  47         <constant>SD_PATH_SYSTEM_STATE_LOGS</constant>,
  48         <constant>SD_PATH_SYSTEM_STATE_CACHE</constant>,
  49         <constant>SD_PATH_SYSTEM_STATE_SPOOL</constant>,
  50
  51         <constant>SD_PATH_USER_BINARIES</constant>,
  52         <constant>SD_PATH_USER_LIBRARY_PRIVATE</constant>,
  53         <constant>SD_PATH_USER_LIBRARY_ARCH</constant>,
  54         <constant>SD_PATH_USER_SHARED</constant>,
  55
  56         <constant>SD_PATH_USER_CONFIGURATION</constant>,
  57         <constant>SD_PATH_USER_RUNTIME</constant>,
  58         <constant>SD_PATH_USER_STATE_PRIVATE</constant>,
  59         <constant>SD_PATH_USER_STATE_CACHE</constant>,
  60
  61         <constant>SD_PATH_USER</constant>,
  62         <constant>SD_PATH_USER_DOCUMENTS</constant>,
  63         <constant>SD_PATH_USER_MUSIC</constant>,
  64         <constant>SD_PATH_USER_PICTURES</constant>,
  65         <constant>SD_PATH_USER_VIDEOS</constant>,
  66         <constant>SD_PATH_USER_DOWNLOAD</constant>,
  67         <constant>SD_PATH_USER_PUBLIC</constant>,
  68         <constant>SD_PATH_USER_TEMPLATES</constant>,
  69         <constant>SD_PATH_USER_DESKTOP</constant>,
  70
  71         <constant>SD_PATH_SEARCH_BINARIES</constant>,
  72         <constant>SD_PATH_SEARCH_BINARIES_DEFAULT</constant>,
  73         <constant>SD_PATH_SEARCH_LIBRARY_PRIVATE</constant>,
  74         <constant>SD_PATH_SEARCH_LIBRARY_ARCH</constant>,
  75         <constant>SD_PATH_SEARCH_SHARED</constant>,
  76         <constant>SD_PATH_SEARCH_CONFIGURATION_FACTORY</constant>,
  77         <constant>SD_PATH_SEARCH_STATE_FACTORY</constant>,
  78         <constant>SD_PATH_SEARCH_CONFIGURATION</constant>,
  79
  80         <constant>SD_PATH_SYSTEMD_UTIL</constant>,
  81         <constant>SD_PATH_SYSTEMD_SYSTEM_UNIT</constant>,
  82         <constant>SD_PATH_SYSTEMD_SYSTEM_PRESET</constant>,
  83         <constant>SD_PATH_SYSTEMD_USER_UNIT</constant>,
  84         <constant>SD_PATH_SYSTEMD_USER_PRESET</constant>,
  85         <constant>SD_PATH_SYSTEMD_SYSTEM_CONF</constant>,
  86         <constant>SD_PATH_SYSTEMD_USER_CONF</constant>,
  87         <constant>SD_PATH_SYSTEMD_SEARCH_SYSTEM_UNIT</constant>,
  88         <constant>SD_PATH_SYSTEMD_SEARCH_USER_UNIT</constant>,
  89         <constant>SD_PATH_SYSTEMD_SYSTEM_GENERATOR</constant>,
  90         <constant>SD_PATH_SYSTEMD_USER_GENERATOR</constant>,
  91         <constant>SD_PATH_SYSTEMD_SEARCH_SYSTEM_GENERATOR</constant>,
  92         <constant>SD_PATH_SYSTEMD_SEARCH_USER_GENERATOR</constant>,
  93         <constant>SD_PATH_SYSTEMD_SLEEP</constant>,
  94         <constant>SD_PATH_SYSTEMD_SHUTDOWN</constant>,
  95
  96         <constant>SD_PATH_TMPFILES</constant>,
  97         <constant>SD_PATH_SYSUSERS</constant>,
  98         <constant>SD_PATH_SYSCTL</constant>,
  99         <constant>SD_PATH_BINFMT</constant>,
 100         <constant>SD_PATH_MODULES_LOAD</constant>,
 101         <constant>SD_PATH_CATALOG</constant>,
 102
 103         <constant>SD_PATH_SYSTEMD_SEARCH_NETWORK</constant>,
 104
 105         <constant>SD_PATH_SYSTEMD_SYSTEM_ENVIRONMENT_GENERATOR</constant>,
 106         <constant>SD_PATH_SYSTEMD_USER_ENVIRONMENT_GENERATOR</constant>,
 107         <constant>SD_PATH_SYSTEMD_SEARCH_SYSTEM_ENVIRONMENT_GENERATOR</constant>,
 108         <constant>SD_PATH_SYSTEMD_SEARCH_USER_ENVIRONMENT_GENERATOR</constant>,
 109 };</funcsynopsisinfo>
 110
 111       <funcprototype>
 112         <funcdef>int <function>sd_path_lookup</function></funcdef>
 113         <paramdef>uint64_t <parameter>type</parameter></paramdef>
 114         <paramdef>const char *<parameter>suffix</parameter></paramdef>
 115         <paramdef>char **<parameter>paths</parameter></paramdef>
 116       </funcprototype>
 117
 118       <funcprototype>
 119         <funcdef>int <function>sd_path_lookup_strv</function></funcdef>
 120         <paramdef>uint64_t <parameter>type</parameter></paramdef>
 121         <paramdef>const char *<parameter>suffix</parameter></paramdef>
 122         <paramdef>char ***<parameter>paths</parameter></paramdef>
 123       </funcprototype>
 124     </funcsynopsis>
 125   </refsynopsisdiv>
 126
 127   <refsect1>
 128     <title>Description</title>
 129
 130     <para><function>sd_path_lookup()</function> and <function>sd_bus_path_lookup_strv()</function> return a
 131     single path or set of file system paths specified by the argument <parameter>type</parameter>. In case of
 132     <function>sd_path_lookup()</function> a single <constant>NUL</constant>-terminated string is returned.
 133     When <parameter>type</parameter> specifies a set of paths, they are concatenated using
 134     <literal>:</literal> as a separator (as is traditionally done for e.g. <varname>$PATH</varname> or
 135     <varname>$LD_LIBRARY_PATH</varname>). In case of <function>sd_path_lookup_strv()</function> a
 136     <constant>NULL</constant>-terminated array of strings is returned (strv). If suffix
 137     <parameter>suffix</parameter> is given, it is concatenated to each of the paths after a slash
 138     (<literal>/</literal>). All returned paths are absolute.</para>
 139
 140     <para>For paths which refer to user directories, the relevant XDG standard is followed, with support for
 141     environment variables like <varname>$XDG_DOCUMENTS_DIR</varname>, <varname>$XDG_DESKTOP_DIR</varname>,
 142     ..., and explicit configuration in <filename>/etc/xdg/user-dirs.conf</filename> or
 143     <filename>${XDG_CONFIG_HOME}/user-dirs.dirs</filename>. See
 144     <ulink url="https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html">
 145       XDG Base Directory Specification</ulink> for details.</para>
 146
 147     <para><citerefentry><refentrytitle>systemd-path</refentrytitle><manvolnum>1</manvolnum></citerefentry> is
 148     a wrapper around <function>sd_path_lookup()</function> and allows the same set of paths to be queried.
 149     </para>
 150   </refsect1>
 151
 152   <refsect1>
 153     <title>Return Value</title>
 154
 155     <para>On success, <function>sd_path_lookup()</function> and <function>sd_path_lookup_strv()</function>
 156     return a non-negative integer. On failure, a negative errno-style error number is returned by either
 157     function.</para>
 158
 159     <para>The returned string or string array (strv) must be
 160     <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>'d by the
 161     caller.</para>
 162
 163     <refsect2 id='errors'>
 164       <title>Errors</title>
 165
 166       <para>Returned errors may indicate the following problems:</para>
 167
 168       <variablelist>
 169         <varlistentry>
 170           <term><constant>-EOPNOTSUPP</constant></term>
 171
 172           <listitem><para>Unknown identifier <parameter>type</parameter>.</para>
 173
 174           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 175         </varlistentry>
 176
 177         <varlistentry>
 178           <term><constant>-EINVAL</constant></term>
 179
 180           <listitem><para>Output argument is <constant>NULL</constant>.</para>
 181
 182           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 183         </varlistentry>
 184
 185         <varlistentry>
 186           <term><constant>-ENXIO</constant></term>
 187
 188           <listitem><para>Query failed because of an undefined environment variable (e.g. for
 189           <constant>SD_PATH_USER_RUNTIME</constant> when <varname>$XDG_RUNTIME_DIR</varname> is not
 190           defined).</para>
 191
 192           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 193         </varlistentry>
 194
 195         <varlistentry>
 196           <term><constant>-ENOMEM</constant></term>
 197
 198           <listitem><para>Memory allocation failed.</para>
 199
 200           <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 201         </varlistentry>
 202       </variablelist>
 203     </refsect2>
 204   </refsect1>
 205
 206   <refsect1>
 207     <title>Examples</title>
 208
 209     <refsect2>
 210       <title>Look up the location of ~/Documents</title>
 211
 212       <programlisting><xi:include href="path-documents.c" parse="text" /></programlisting>
 213       <para>Note that the default answer of <filename index='false'>$HOME/Documents</filename> may be
 214       overridden by <filename index='false'>user-dirs.conf</filename> or
 215       <varname>$XDG_DOCUMENTS_DIR</varname>.</para>
 216     </refsect2>
 217   </refsect1>
 218
 219   <xi:include href="libsystemd-pkgconfig.xml" />
 220
 221   <refsect1>
 222     <title>History</title>
 223     <para><function>sd_path_lookup()</function> and
 224     <function>sd_path_lookup_strv()</function> were added in version 246.</para>
 225   </refsect1>
 226
 227   <refsect1>
 228     <title>See Also</title>
 229
 230     <para>
 231       <citerefentry><refentrytitle>systemd-path</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 232     </para>
 233   </refsect1>
 234
 235 </refentry>