journalctl: add --image= switch

[thirdparty/systemd.git] / man / systemd-tmpfiles.xml

<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1+ -->

<refentry id="systemd-tmpfiles"
    xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>systemd-tmpfiles</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemd-tmpfiles</refentrytitle>
    <manvolnum>8</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemd-tmpfiles</refname>
    <refname>systemd-tmpfiles-setup.service</refname>
    <refname>systemd-tmpfiles-setup-dev.service</refname>
    <refname>systemd-tmpfiles-clean.service</refname>
    <refname>systemd-tmpfiles-clean.timer</refname>
    <refpurpose>Creates, deletes and cleans up volatile
    and temporary files and directories</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>systemd-tmpfiles</command>
      <arg choice="opt" rep="repeat">OPTIONS</arg>
      <arg choice="opt" rep="repeat"><replaceable>CONFIGFILE</replaceable></arg>
    </cmdsynopsis>

    <para>System units:
<literallayout><filename>systemd-tmpfiles-setup.service</filename>
<filename>systemd-tmpfiles-setup-dev.service</filename>
<filename>systemd-tmpfiles-clean.service</filename>
<filename>systemd-tmpfiles-clean.timer</filename></literallayout></para>

    <para>User units:
<literallayout><filename>systemd-tmpfiles-setup.service</filename>
<filename>systemd-tmpfiles-clean.service</filename>
<filename>systemd-tmpfiles-clean.timer</filename></literallayout></para>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><command>systemd-tmpfiles</command> creates, deletes, and
    cleans up volatile and temporary files and directories, based on
    the configuration file format and location specified in
    <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
    </para>

    <para>If invoked with no arguments, it applies all directives from all configuration
    files. When invoked with <option>--replace=<replaceable>PATH</replaceable></option>,
    arguments specified on the command line are used instead of the configuration file
    <replaceable>PATH</replaceable>. Otherwise, if one or more absolute filenames are
    passed on the command line, only the directives in these files are applied. If
    <literal>-</literal> is specified instead of a filename, directives are read from
    standard input. If only the basename of a configuration file is specified, all
    configuration directories as specified in
    <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    are searched for a matching file and the file found that has the highest priority is
    executed.</para>

    <para>System services (<filename>systemd-tmpfiles-setup.service</filename>,
    <filename>systemd-tmpfiles-setup-dev.service</filename>,
    <filename>systemd-tmpfiles-clean.service</filename>) invoke <command>systemd-tmpfiles</command> to create
    system files and to perform system wide cleanup. Those services read administrator-controlled
    configuration files in <filename>tmpfiles.d/</filename> directories. User services
    (<filename>systemd-tmpfiles-setup.service</filename>,
    <filename>systemd-tmpfiles-clean.service</filename>) also invoke <command>systemd-tmpfiles</command>, but
    it reads a separate set of files, which includes user-controlled files under
    <filename>~/.config/user-tmpfiles.d/</filename> and <filename>~/.local/share/user-tmpfiles.d/</filename>,
    and administrator-controller files under <filename>/usr/share/user-tmpfiles.d/</filename>. Users may use
    this to create and clean up files under their control, but the system instance performs global cleanup
    and is not influenced by user configuration. Note that this means a time-based cleanup configured in the
    system instance, such as the one typically configured for <filename>/tmp</filename>, will thus also
    affect files created by the user instance if they are placed in <filename>/tmp</filename>, even if the
    user instance's time-based cleanup is turned off.</para>
  </refsect1>

  <refsect1>
    <title>Options</title>

    <para>The following options are understood:</para>

    <variablelist>
      <varlistentry>
        <term><option>--create</option></term>
        <listitem><para>If this option is passed, all files and
        directories marked with
        <varname>f</varname>,
        <varname>F</varname>,
        <varname>w</varname>,
        <varname>d</varname>,
        <varname>D</varname>,
        <varname>v</varname>,
        <varname>p</varname>,
        <varname>L</varname>,
        <varname>c</varname>,
        <varname>b</varname>,
        <varname>m</varname>
        in the configuration files are created or written to. Files
        and directories marked with
        <varname>z</varname>,
        <varname>Z</varname>,
        <varname>t</varname>,
        <varname>T</varname>,
        <varname>a</varname>, and
        <varname>A</varname> have their ownership, access mode and
        security labels set.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--clean</option></term>
        <listitem><para>If this option is passed, all files and
        directories with an age parameter configured will be cleaned
        up.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--remove</option></term>
        <listitem><para>If this option is passed, the contents of
        directories marked with <varname>D</varname> or
        <varname>R</varname>, and files or directories themselves
        marked with <varname>r</varname> or <varname>R</varname> are
        removed.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--user</option></term>
        <listitem><para>Execute "user" configuration, i.e. <filename>tmpfiles.d</filename>
        files in user configuration directories.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--boot</option></term>
        <listitem><para>Also execute lines with an exclamation mark.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--prefix=<replaceable>path</replaceable></option></term>
        <listitem><para>Only apply rules with paths that start with
        the specified prefix. This option can be specified multiple
        times.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--exclude-prefix=<replaceable>path</replaceable></option></term>
        <listitem><para>Ignore rules with paths that start with the
        specified prefix. This option can be specified multiple
        times.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-E</option></term>
        <listitem><para>A shortcut for <literal>--exclude-prefix=/dev --exclude-prefix=/proc
        --exclude-prefix=/run --exclude-prefix=/sys</literal>, i.e. exclude the hierarchies typically backed
        by virtual or memory file systems. This is useful in combination with <option>--root=</option>, if
        the specified directory tree contains an OS tree without these virtual/memory file systems mounted
        in, as it is typically not desirable to create any files and directories below these subdirectories
        if they are supposed to be overmounted during runtime.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--root=<replaceable>root</replaceable></option></term>
        <listitem><para>Takes a directory path as an argument. All paths will be prefixed with the given alternate
        <replaceable>root</replaceable> path, including config search paths.</para>

        <para>When this option is used, the libc Name Service Switch (NSS) is bypassed for resolving users
        and groups. Instead the files <filename>/etc/passwd</filename> and <filename>/etc/group</filename>
        inside the alternate root are read directly. This means that users/groups not listed in these files
        will not be resolved, i.e. LDAP NIS and other complex databases are not considered.</para>

        <para>Consider combining this with <option>-E</option> to ensure the invocation does not create files
        or directories below mount points in the OS image operated on that are typically overmounted during
        runtime.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--replace=<replaceable>PATH</replaceable></option></term>
        <listitem><para>When this option is given, one ore more positional arguments
        must be specified. All configuration files found in the directories listed in
        <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        will be read, and the configuration given on the command line will be
        handled instead of and with the same priority as the configuration file
        <replaceable>PATH</replaceable>.</para>

        <para>This option is intended to be used when package installation scripts
        are running and files belonging to that package are not yet available on
        disk, so their contents must be given on the command line, but the admin
        configuration might already exist and should be given higher priority.
        </para></listitem>
      </varlistentry>

      <xi:include href="standard-options.xml" xpointer="cat-config" />
      <xi:include href="standard-options.xml" xpointer="no-pager" />
      <xi:include href="standard-options.xml" xpointer="help" />
      <xi:include href="standard-options.xml" xpointer="version" />
    </variablelist>

    <para>It is possible to combine <option>--create</option>, <option>--clean</option>, and <option>--remove</option>
    in one invocation (in which case removal and cleanup are executed before creation of new files). For example,
    during boot the following command line is executed to ensure that all temporary and volatile directories are
    removed and created according to the configuration file:</para>

    <programlisting>systemd-tmpfiles --remove --create</programlisting>
  </refsect1>

  <refsect1>
    <title>Unprivileged --cleanup operation</title>

    <para><command>systemd-tmpfiles</command> tries to avoid changing
    the access and modification times on the directories it accesses,
    which requires <constant>CAP_FOWNER</constant> privileges. When
    running as non-root, directories which are checked for files to
    clean up will have their access time bumped, which might prevent
    their cleanup.
    </para>
  </refsect1>

  <refsect1>
    <title>Exit status</title>

    <para>On success, 0 is returned. If the configuration was syntactically invalid (syntax errors,
    missing arguments, …), so some lines had to be ignored, but no other errors occurred,
    <constant>65</constant> is returned (<constant>EX_DATAERR</constant> from
    <filename>/usr/include/sysexits.h</filename>). If the configuration was syntactically valid, but
    could not be executed (lack of permissions, creation of files in missing directories, invalid
    contents when writing to <filename>/sys/</filename> values, …), <constant>73</constant> is
    returned (<constant>EX_CANTCREAT</constant> from <filename>/usr/include/sysexits.h</filename>).
    Otherwise, <constant>1</constant> is returned (<constant>EXIT_FAILURE</constant> from
    <filename>/usr/include/stdlib.h</filename>).
    </para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>