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+<?xml version='1.0'?>
+<!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-or-later
+
+ Copyright © 2010 Brandon Philips
+-->
+<refentry id="tmpfiles.d"
+ xmlns:xi="http://www.w3.org/2001/XInclude">
+
+ <refentryinfo>
+ <title>tmpfiles.d</title>
+ <productname>systemd</productname>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>tmpfiles.d</refentrytitle>
+ <manvolnum>5</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>tmpfiles.d</refname>
+ <refpurpose>Configuration for creation, deletion and cleaning of
+ volatile and temporary files</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <para><literallayout><filename>/etc/tmpfiles.d/*.conf</filename>
+<filename>/run/tmpfiles.d/*.conf</filename>
+<filename>/usr/lib/tmpfiles.d/*.conf</filename>
+ </literallayout></para>
+
+ <para><literallayout><filename>~/.config/user-tmpfiles.d/*.conf</filename>
+<filename>$XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf</filename>
+<filename>~/.local/share/user-tmpfiles.d/*.conf</filename>
+<filename index='false'>…</filename>
+<filename>/usr/share/user-tmpfiles.d/*.conf</filename>
+ </literallayout></para>
+
+ <programlisting>#Type Path Mode User Group Age Argument
+f /file/to/create mode user group - content
+f+ /file/to/create-or-truncate mode user group - content
+w /file/to/write-to - - - - content
+w+ /file/to/append-to - - - - content
+d /directory/to/create-and-clean-up mode user group cleanup-age -
+D /directory/to/create-and-remove mode user group cleanup-age -
+e /directory/to/clean-up mode user group cleanup-age -
+v /subvolume-or-directory/to/create mode user group cleanup-age -
+q /subvolume-or-directory/to/create mode user group cleanup-age -
+Q /subvolume-or-directory/to/create mode user group cleanup-age -
+p /fifo/to/create mode user group - -
+p+ /fifo/to/[re]create mode user group - -
+L /symlink/to/create - - - - symlink/target/path
+L+ /symlink/to/[re]create - - - - symlink/target/path
+c /dev/char-device-to-create mode user group - major:minor
+c+ /dev/char-device-to-[re]create mode user group - major:minor
+b /dev/block-device-to-create mode user group - major:minor
+b+ /dev/block-device-to-[re]create mode user group - major:minor
+C /target/to/create - - - cleanup-age /source/to/copy
+x /path-or-glob/to/ignore/recursively - - - cleanup-age -
+X /path-or-glob/to/ignore - - - cleanup-age -
+r /path-or-glob/to/remove - - - - -
+R /path-or-glob/to/remove/recursively - - - - -
+z /path-or-glob/to/adjust/mode mode user group - -
+Z /path-or-glob/to/adjust/mode/recursively mode user group - -
+t /path-or-glob/to/set/xattrs - - - - xattrs
+T /path-or-glob/to/set/xattrs/recursively - - - - xattrs
+h /path-or-glob/to/set/attrs - - - - file attrs
+H /path-or-glob/to/set/attrs/recursively - - - - file attrs
+a /path-or-glob/to/set/acls - - - - POSIX ACLs
+a+ /path-or-glob/to/append/acls - - - - POSIX ACLs
+A /path-or-glob/to/set/acls/recursively - - - - POSIX ACLs
+A+ /path-or-glob/to/append/acls/recursively - - - - POSIX ACLs
+
+</programlisting>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><filename>tmpfiles.d</filename> configuration files provide a generic mechanism to define the
+ <emphasis>creation</emphasis> of regular files, directories, pipes, and device nodes, adjustments to
+ their <emphasis>access mode, ownership, attributes, quota assignments, and contents</emphasis>, and
+ finally their time-based <emphasis>removal</emphasis>. It is mostly commonly used for volatile and
+ temporary files and directories (such as those located under <filename>/run/</filename>,
+ <filename>/tmp/</filename>, <filename>/var/tmp/</filename>, the API file systems such as
+ <filename>/sys/</filename> or <filename>/proc/</filename>, as well as some other directories below
+ <filename>/var/</filename>).</para>
+
+ <para><command>systemd-tmpfiles</command> uses this configuration to create volatile files and
+ directories during boot and to do periodic cleanup afterwards. See
+ <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
+ the description of <filename>systemd-tmpfiles-setup.service</filename>,
+ <filename>systemd-tmpfiles-clean.service</filename>, and associated units.</para>
+
+ <para>System daemons frequently require private runtime directories below <filename>/run/</filename> to
+ store communication sockets and similar. For these, it is better to use
+ <varname>RuntimeDirectory=</varname> in their unit files (see
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details), if the flexibility provided by <filename>tmpfiles.d</filename> is not required. The advantages
+ are that the configuration required by the unit is centralized in one place, and that the lifetime of the
+ directory is tied to the lifetime of the service itself. Similarly, <varname>StateDirectory=</varname>,
+ <varname>CacheDirectory=</varname>, <varname>LogsDirectory=</varname>, and
+ <varname>ConfigurationDirectory=</varname> should be used to create directories under
+ <filename>/var/lib/</filename>, <filename>/var/cache/</filename>, <filename>/var/log/</filename>, and
+ <filename>/etc/</filename>. <filename>tmpfiles.d</filename> should be used for files whose lifetime is
+ independent of any service or requires more complicated configuration.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Configuration Directories and Precedence</title>
+
+ <para>Each configuration file shall be named in the style of
+ <filename><replaceable>package</replaceable>.conf</filename> or
+ <filename><replaceable>package</replaceable>-<replaceable>part</replaceable>.conf</filename>.
+ The second variant should be used when it is desirable to make it
+ easy to override just this part of configuration.</para>
+
+ <para>Files in <filename>/etc/tmpfiles.d</filename> override files with the same name in
+ <filename>/usr/lib/tmpfiles.d</filename> and <filename>/run/tmpfiles.d</filename>. Files in
+ <filename>/run/tmpfiles.d</filename> override files with the same name in
+ <filename>/usr/lib/tmpfiles.d</filename>. Packages should install their configuration files in
+ <filename>/usr/lib/tmpfiles.d</filename>. Files in <filename>/etc/tmpfiles.d</filename> are reserved for
+ the local administrator, who may use this logic to override the configuration files installed by vendor
+ packages. All configuration files are sorted by their filename in lexicographic order, regardless of
+ which of the directories they reside in. If multiple files specify the same path, the entry in the file
+ with the lexicographically earliest name will be applied (note that lines suppressed due to the
+ <literal>!</literal> are filtered before application, meaning that if an early line carries the
+ exclamation mark and is suppressed because of that, a later line matching in path will be applied). All
+ other conflicting entries will be logged as errors. When two lines are prefix path and suffix path of
+ each other, then the prefix line is always created first, the suffix later (and if removal applies to the
+ line, the order is reversed: the suffix is removed first, the prefix later). Lines that take globs are
+ applied after those accepting no globs. If multiple operations shall be applied on the same file (such as
+ ACL, xattr, file attribute adjustments), these are always done in the same fixed order. Except for those
+ cases, the files/directories are processed in the order they are listed.</para>
+
+ <para>If the administrator wants to disable a configuration file
+ supplied by the vendor, the recommended way is to place a symlink
+ to <filename>/dev/null</filename> in
+ <filename>/etc/tmpfiles.d/</filename> bearing the same filename.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>Configuration File Format</title>
+
+ <para>The configuration format is one line per path, containing type, path, mode, ownership, age, and
+ argument fields. The lines are separated by newlines, the fields by whitespace:</para>
+
+ <programlisting>#Type Path Mode User Group Age Argument…
+d /run/user 0755 root root 10d -
+L /tmp/foobar - - - - /dev/null</programlisting>
+
+ <para>Fields may contain C-style escapes. With the exception of the seventh field (the "argument") all
+ fields may be enclosed in quotes. Note that any whitespace found in the line after the beginning of the
+ argument field will be considered part of the argument field. To begin the argument field with a
+ whitespace character, use C-style escapes (e.g. <literal>\x20</literal>).</para>
+
+ <refsect2>
+ <title>Type</title>
+
+ <para>The type consists of a single letter and optionally one or emore modifier characters: a plus sign
+ (<literal>+</literal>), exclamation mark (<literal>!</literal>), minus sign (<literal>-</literal>),
+ equals sign (<literal>=</literal>), tilde character (<literal>~</literal>) and/or caret
+ (<literal>^</literal>).</para>
+
+ <para>The following line types are understood:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><varname>f</varname></term>
+ <term><varname>f+</varname></term>
+ <listitem><para><varname>f</varname> will create a file if it does not exist yet. If the argument
+ parameter is given and the file did not exist yet, it will be written to the file.
+ <varname>f+</varname> will create or truncate the file. If the argument parameter is given, it will
+ be written to the file. Does not follow symlinks.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>w</varname></term>
+ <term><varname>w+</varname></term>
+ <listitem><para>Write the argument parameter to a file, if the file exists.
+ If suffixed with <varname>+</varname>, the line will be appended to the file.
+ If your configuration writes multiple lines to the same file, use <varname>w+</varname>.
+ Lines of this type accept shell-style globs in place of normal path names.
+ The argument parameter will be written without a trailing newline.
+ C-style backslash escapes are interpreted. Follows symlinks.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>d</varname></term>
+ <listitem><para>Create a directory. The mode and ownership will be adjusted if specified. Contents
+ of this directory are subject to time-based cleanup if the age argument is specified.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>D</varname></term>
+ <listitem><para>Similar to <varname>d</varname>, but in addition the contents of the directory will
+ be removed when <option>--remove</option> is used.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>e</varname></term>
+ <listitem><para>Adjust the mode and ownership of existing directories and remove their contents
+ based on age.
+ Lines of this type accept shell-style globs in place of normal path names. Contents of the
+ directories are subject to time-based cleanup if the age argument is specified. If the age argument
+ is <literal>0</literal>, contents will be unconditionally deleted every time
+ <command>systemd-tmpfiles --clean</command> is run.</para>
+
+ <para>For this entry to be useful, at least one of the mode, user, group, or age arguments must be
+ specified, since otherwise this entry has no effect. As an exception, an entry with no effect may
+ be useful when combined with <varname>!</varname>, see the examples.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>v</varname></term>
+ <listitem><para>Create a subvolume if the path does not exist yet, the file system supports
+ subvolumes (btrfs), and the system itself is installed into a subvolume (specifically: the root
+ directory <filename>/</filename> is itself a subvolume). Otherwise, create a normal directory, in
+ the same way as <varname>d</varname>.</para>
+
+ <para>A subvolume created with this line type is not assigned to any higher-level quota group. For
+ that, use <varname>q</varname> or <varname>Q</varname>, which allow creating simple quota group
+ hierarchies, see below.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>q</varname></term>
+ <listitem><para>Create a subvolume or directory the same as <varname>v</varname>, but assign the
+ subvolume to the same higher-level quota groups as the parent. This ensures that higher-level
+ limits and accounting applied to the parent subvolume also include the specified subvolume. On
+ non-btrfs file systems, this line type is identical to <varname>d</varname>.</para>
+
+ <para>If the subvolume already exists, no change to the quota hierarchy is made, regardless of whether the
+ subvolume is already attached to a quota group or not. Also see <varname>Q</varname> below. See <citerefentry
+ project='die-net'><refentrytitle>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
+ details about the btrfs quota group concept.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Q</varname></term>
+ <listitem><para>Create the subvolume or directory the same as <varname>v</varname>, but assign the
+ new subvolume to a new leaf quota group. Instead of copying the higher-level quota group
+ assignments from the parent as is done with <varname>q</varname>, the lowest quota group of the
+ parent subvolume is determined that is not the leaf quota group. Then, an "intermediary" quota
+ group is inserted that is one level below this level, and shares the same ID part as the specified
+ subvolume. If no higher-level quota group exists for the parent subvolume, a new quota group at
+ level 255 sharing the same ID as the specified subvolume is inserted instead. This new intermediary
+ quota group is then assigned to the parent subvolume's higher-level quota groups, and the specified
+ subvolume's leaf quota group is assigned to it.</para>
+
+ <para>Effectively, this has a similar effect as <varname>q</varname>, however introduces a new higher-level
+ quota group for the specified subvolume that may be used to enforce limits and accounting to the specified
+ subvolume and children subvolume created within it. Thus, by creating subvolumes only via
+ <varname>q</varname> and <varname>Q</varname>, a concept of "subtree quotas" is implemented. Each subvolume
+ for which <varname>Q</varname> is set will get a "subtree" quota group created, and all child subvolumes
+ created within it will be assigned to it. Each subvolume for which <varname>q</varname> is set will not get
+ such a "subtree" quota group, but it is ensured that they are added to the same "subtree" quota group as
+ their immediate parents.</para>
+
+ <para>It is recommended to use <varname>Q</varname> for subvolumes that typically contain further subvolumes,
+ and where it is desirable to have accounting and quota limits on all child subvolumes together. Examples for
+ <varname>Q</varname> are typically <filename>/home/</filename> or <filename>/var/lib/machines/</filename>. In
+ contrast, <varname>q</varname> should be used for subvolumes that either usually do not include further
+ subvolumes or where no accounting and quota limits are needed that apply to all child subvolumes
+ together. Examples for <varname>q</varname> are typically <filename>/var/</filename> or
+ <filename>/var/tmp/</filename>. </para>
+
+ <para>As with <varname>q</varname>, <varname>Q</varname> has no effect on the quota group hierarchy if the
+ subvolume already exists, regardless of whether the subvolume already belong to a quota group or not.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>p</varname></term>
+ <term><varname>p+</varname></term>
+ <listitem><para>Create a named pipe (FIFO) if it does not
+ exist yet. If suffixed with <varname>+</varname> and a file
+ already exists where the pipe is to be created, it will be
+ removed and be replaced by the pipe.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>L</varname></term>
+ <term><varname>L+</varname></term>
+ <listitem><para>Create a symlink if it does not exist
+ yet. If suffixed with <varname>+</varname> and a file or
+ directory already exists where the symlink is to be created,
+ it will be removed and be replaced by the symlink. If the
+ argument is omitted, symlinks to files with the same name
+ residing in the directory
+ <filename>/usr/share/factory/</filename> are created. Note
+ that permissions and ownership on symlinks are ignored.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>c</varname></term>
+ <term><varname>c+</varname></term>
+ <listitem><para>Create a character device node if it does
+ not exist yet. If suffixed with <varname>+</varname> and a
+ file already exists where the device node is to be created,
+ it will be removed and be replaced by the device node. It is
+ recommended to suffix this entry with an exclamation mark to
+ only create static device nodes at boot, as udev will not
+ manage static device nodes that are created at runtime.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>b</varname></term>
+ <term><varname>b+</varname></term>
+ <listitem><para>Create a block device node if it does not
+ exist yet. If suffixed with <varname>+</varname> and a file
+ already exists where the device node is to be created, it
+ will be removed and be replaced by the device node. It is
+ recommended to suffix this entry with an exclamation mark to
+ only create static device nodes at boot, as udev will not
+ manage static device nodes that are created at runtime.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>C</varname></term>
+ <listitem><para>Recursively copy a file or directory, if the
+ destination files or directories do not exist yet or the
+ destination directory is empty. Note that this command will not
+ descend into subdirectories if the destination directory already
+ exists and is not empty. Instead, the entire copy operation is
+ skipped. If the argument is omitted, files from the source directory
+ <filename>/usr/share/factory/</filename> with the same name
+ are copied. Does not follow symlinks. Contents of the directories
+ are subject to time-based cleanup if the age argument is specified.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>x</varname></term>
+ <listitem><para>Ignore a path during cleaning. Use this type
+ to exclude paths from clean-up as controlled with the Age
+ parameter. Note that lines of this type do not influence the
+ effect of <varname>r</varname> or <varname>R</varname>
+ lines. Lines of this type accept shell-style globs in place
+ of normal path names. </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>X</varname></term>
+ <listitem><para>Ignore a path during cleaning. Use this type
+ to exclude paths from clean-up as controlled with the Age
+ parameter. Unlike <varname>x</varname>, this parameter will
+ not exclude the content if path is a directory, but only
+ directory itself. Note that lines of this type do not
+ influence the effect of <varname>r</varname> or
+ <varname>R</varname> lines. Lines of this type accept
+ shell-style globs in place of normal path names.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>r</varname></term>
+ <listitem><para>Remove a file or directory if it exists.
+ This may not be used to remove non-empty directories, use
+ <varname>R</varname> for that. Lines of this type accept
+ shell-style globs in place of normal path
+ names. Does not follow symlinks.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>R</varname></term>
+ <listitem><para>Recursively remove a path and all its
+ subdirectories (if it is a directory). Lines of this type
+ accept shell-style globs in place of normal path
+ names. Does not follow symlinks.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>z</varname></term>
+ <listitem><para>Adjust the access mode, user and group ownership, and restore the SELinux security
+ context of a file or directory, if it exists. Lines of this type accept shell-style globs in place
+ of normal path names. Does not follow symlinks.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Z</varname></term>
+ <listitem><para>Recursively set the access mode, user and group ownership, and restore the SELinux
+ security context of a file or directory if it exists, as well as of its subdirectories and the
+ files contained therein (if applicable). Lines of this type accept shell-style globs in place of
+ normal path names. Does not follow symlinks.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>t</varname></term>
+ <listitem><para>Set extended attributes, see <citerefentry
+ project='man-pages'><refentrytitle>attr</refentrytitle>
+ <manvolnum>5</manvolnum></citerefentry> for details. The argument field should take one or more
+ assignment expressions in the form
+ <replaceable>namespace</replaceable>.<replaceable>attribute</replaceable>=<replaceable>value</replaceable>,
+ for examples see below. Lines of this type accept shell-style globs in place of normal path
+ names. This can be useful for setting SMACK labels. Does not follow symlinks.</para>
+
+ <para>Please note that extended attributes settable with this line type are a different concept
+ from the Linux file attributes settable with <varname>h</varname>/<varname>H</varname>, see
+ below.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>T</varname></term>
+ <listitem><para>Same as <varname>t</varname>, but operates recursively.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>h</varname></term>
+ <listitem><para>Set Linux file/directory attributes. Lines of this type accept shell-style globs in
+ place of normal path names.</para>
+
+ <para>The format of the argument field is <varname>[+-=][aAcCdDeijPsStTu]</varname>. The prefix
+ <varname>+</varname> (the default one) causes the attributes to be added; <varname>-</varname>
+ causes the attributes to be removed; <varname>=</varname> causes the attributes to be set exactly
+ as the following letters. The letters <literal>aAcCdDeijPsStTu</literal> select the new attributes
+ for the files, see <citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle>
+ <manvolnum>1</manvolnum></citerefentry> for further information.
+ </para>
+
+ <para>Passing only <varname>=</varname> as argument resets all the file attributes listed above. It
+ has to be pointed out that the <varname>=</varname> prefix limits itself to the attributes
+ corresponding to the letters listed here. All other attributes will be left untouched. Does not
+ follow symlinks.</para>
+
+ <para>Please note that the Linux file attributes settable with this line type are a different
+ concept from the extended attributes settable with <varname>t</varname>/<varname>T</varname>,
+ see above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>H</varname></term>
+ <listitem><para>Sames as <varname>h</varname>, but operates recursively.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>a</varname></term>
+ <term><varname>a+</varname></term>
+ <listitem><para>Set POSIX ACLs (access control lists), see <citerefentry
+ project='man-pages'><refentrytitle>acl</refentrytitle>
+ <manvolnum>5</manvolnum></citerefentry>. If suffixed with <varname>+</varname>, the specified
+ entries will be added to the existing set. <command>systemd-tmpfiles</command> will automatically
+ add the required base entries for user and group based on the access mode of the file, unless base
+ entries already exist or are explicitly specified. The mask will be added if not specified
+ explicitly or already present. Lines of this type accept shell-style globs in place of normal path
+ names. This can be useful for allowing additional access to certain files. Does not follow
+ symlinks.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>A</varname></term>
+ <term><varname>A+</varname></term>
+ <listitem><para>Same as <varname>a</varname> and
+ <varname>a+</varname>, but recursive. Does not follow
+ symlinks.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect2>
+
+ <refsect2>
+ <title>Type Modifiers</title>
+
+ <para>If the exclamation mark (<literal>!</literal>) is used, this line is only safe to execute during
+ boot, and can break a running system. Lines without the exclamation mark are presumed to be safe to
+ execute at any time, e.g. on package upgrades. <command>systemd-tmpfiles</command> will take lines with
+ an exclamation mark only into consideration, if the <option>--boot</option> option is given.</para>
+
+ <para>For example:
+ <programlisting># Make sure these are created by default so that nobody else can
+d /tmp/.X11-unix 1777 root root 10d
+
+# Unlink the X11 lock files
+r! /tmp/.X[0-9]*-lock</programlisting>
+ The second line in contrast to the first one would break a
+ running system, and will only be executed with
+ <option>--boot</option>.</para>
+
+ <para>If the minus sign (<literal>-</literal>) is used, this line failing to run successfully during
+ create (and only create) will not cause the execution of <command>systemd-tmpfiles</command> to return
+ an error.</para>
+
+ <para>For example:
+ <programlisting># Modify sysfs but don't fail if we are in a container with a read-only /proc
+w- /proc/sys/vm/swappiness - - - - 10</programlisting></para>
+
+ <para>If the equals sign (<literal>=</literal>) is used, the file types of existing objects in the specified path
+ are checked, and removed if they do not match. This includes any implicitly created parent directories (which can
+ be either directories or directory symlinks). For example, if there is a FIFO in place of one of the parent path
+ components it will be replaced with a directory.</para>
+
+ <para>If the tilde character (<literal>~</literal>) is used, the argument (i.e. 6th) column is <ulink
+ url="https://www.rfc-editor.org/rfc/rfc4648.html">Base64 decoded</ulink> before use. This modifier is
+ only supported on line types that can write file contents, i.e. <varname>f</varname>,
+ <varname>f+</varname>, <varname>w</varname>, <varname>+</varname>. This is useful for writing arbitrary
+ binary data (including newlines and NUL bytes) to files. Note that if this switch is used, the argument
+ is not subject to specifier expansion, neither before nor after Base64 decoding.</para>
+
+ <para>If the caret character (<literal>^</literal>) is used, the argument (i.e. 6th) column takes a
+ service credential name to read the argument data from. See <ulink
+ url="https://systemd.io/CREDENTIALS">System and Service Credentials</ulink> for details about the
+ credentials concept. This modifier is only supported on line types that can write file contents,
+ i.e. <varname>f</varname>, <varname>f+</varname>, <varname>w</varname>, <varname>w+</varname>. This is
+ useful for writing arbitrary files with contents sourced from elsewhere, including from VM or container
+ managers further up. If the specified credential is not set for the <command>systemd-tmpfiles</command>
+ service, the line is silently skipped. If <literal>^</literal> and <literal>~</literal> are combined
+ Base64 decoding is applied to the credential contents.</para>
+
+ <para>Note that for all line types that result in creation of any kind of file node
+ (i.e. <varname>f</varname>/<varname>F</varname>,
+ <varname>d</varname>/<varname>D</varname>/<varname>v</varname>/<varname>q</varname>/<varname>Q</varname>,
+ <varname>p</varname>, <varname>L</varname>, <varname>c</varname>/<varname>b</varname> and <varname>C</varname>)
+ leading directories are implicitly created if needed, owned by root with an access mode of 0755. In order to
+ create them with different modes or ownership make sure to add appropriate <varname>d</varname> lines.</para>
+ </refsect2>
+
+ <refsect2>
+ <title>Path</title>
+
+ <para>The file system path specification supports simple
+ specifier expansion, see below. The path (after expansion) must be
+ absolute.</para>
+ </refsect2>
+
+ <refsect2>
+ <title>Mode</title>
+
+ <para>The file access mode to use when creating this file or directory. If omitted or when set to
+ <literal>-</literal>, the default is used: 0755 for directories, 0644 for all other file objects. For
+ <varname>z</varname>, <varname>Z</varname> lines, if omitted or when set to <literal>-</literal>, the
+ file access mode will not be modified. This parameter is ignored for <varname>x</varname>,
+ <varname>r</varname>, <varname>R</varname>, <varname>L</varname>, <varname>t</varname>, and
+ <varname>a</varname> lines.</para>
+
+ <para>Optionally, if prefixed with <literal>~</literal>, the access mode is masked based on the already
+ set access bits for existing file or directories: if the existing file has all executable bits unset,
+ all executable bits are removed from the new access mode, too. Similarly, if all read bits are removed
+ from the old access mode, they will be removed from the new access mode too, and if all write bits are
+ removed, they will be removed from the new access mode too. In addition, the sticky/SUID/SGID bit is
+ removed unless applied to a directory. This functionality is particularly useful in conjunction with
+ <varname>Z</varname>.</para>
+
+ <para>By default the access mode of listed inodes is set to the specified mode regardless if it is
+ created anew, or already existed. Optionally, if prefixed with <literal>:</literal>, the configured
+ access mode is only applied when creating new inodes, and if the inode the line refers to
+ already exists, its access mode is left in place unmodified.</para>
+ </refsect2>
+
+ <refsect2>
+ <title>User, Group</title>
+
+ <para>The user and group to use for this file or directory. This may either be a numeric ID or a
+ user/group name. If omitted or when set to <literal>-</literal>, the user and group of the user who
+ invokes <command>systemd-tmpfiles</command> is used. For <varname>z</varname> and <varname>Z</varname>
+ lines, when omitted or when set to <literal>-</literal>, the file ownership will not be modified. These
+ parameters are ignored for <varname>x</varname>, <varname>r</varname>, <varname>R</varname>,
+ <varname>L</varname>, <varname>t</varname>, and <varname>a</varname> lines.</para>
+
+ <para>This field should generally only reference system users/groups, i.e. users/groups that are
+ guaranteed to be resolvable during early boot. If this field references users/groups that only become
+ resolveable during later boot (i.e. after NIS, LDAP or a similar networked directory service become
+ available), execution of the operations declared by the line will likely fail. Also see <ulink
+ url="https://systemd.io/UIDS-GIDS/#notes-on-resolvability-of-user-and-group-names">Notes on
+ Resolvability of User and Group Names</ulink> for more information on requirements on system user/group
+ definitions.</para>
+
+ <para>By default the ownership of listed inodes is set to the specified user/group regardless if it is
+ created anew, or already existed. Optionally, if prefixed with <literal>:</literal>, the configured
+ user/group information is only applied when creating new inodes, and if the inode the line refers to
+ already exists, its user/group is left in place unmodified.</para>
+ </refsect2>
+
+ <refsect2>
+ <title>Age</title>
+
+ <para>The date field, when set, is used to decide what files to
+ delete when cleaning. If a file or directory is older than the
+ current time minus the age field, it is deleted. The field
+ format is a series of integers each followed by one of the
+ following suffixes for the respective time units:
+ <constant>s</constant>,
+ <constant>m</constant> or <constant>min</constant>,
+ <constant>h</constant>,
+ <constant>d</constant>,
+ <constant>w</constant>,
+ <constant>ms</constant>, and
+ <constant>us</constant>,
+ meaning seconds, minutes, hours, days, weeks,
+ milliseconds, and microseconds, respectively. Full names of the time units can
+ be used too.
+ </para>
+
+ <para>If multiple integers and units are specified, the time
+ values are summed. If an integer is given without a unit,
+ <constant>s</constant> is assumed.
+ </para>
+
+ <para>When the age is set to zero, the files are cleaned
+ unconditionally.</para>
+
+ <para>The age field only applies to lines starting with
+ <varname>d</varname>, <varname>D</varname>, <varname>e</varname>,
+ <varname>v</varname>, <varname>q</varname>,
+ <varname>Q</varname>, <varname>C</varname>, <varname>x</varname>
+ and <varname>X</varname>. If omitted or set to
+ <literal>-</literal>, no automatic clean-up is done.</para>
+
+ <para>If the age field starts with a tilde character <literal>~</literal>, clean-up is only applied to
+ files and directories one level inside the directory specified, but not the files and directories
+ immediately inside it.</para>
+
+ <para>The age of a file system entry is determined from its last
+ modification timestamp (mtime), its last access timestamp (atime),
+ and (except for directories) its last status change timestamp
+ (ctime). By default, any of these three (or two) values will
+ prevent cleanup if it is more recent than the current time minus
+ the age field. To restrict the deletion based on particular type
+ of file timestamps, the age-by argument can be used.</para>
+
+ <para>The age-by argument overrides the timestamp types to be used for the age check. It can be
+ specified by prefixing the age argument with a sequence of characters to specify the timestamp types
+ and a colon (<literal>:</literal>):
+ <literal><replaceable>age-by</replaceable>...:<replaceable>cleanup-age</replaceable></literal>. The
+ argument can consist of <constant>a</constant> (<constant>A</constant> for directories),
+ <constant>b</constant> (<constant>B</constant> for directories), <constant>c</constant>
+ (<constant>C</constant> for directories), or <constant>m</constant> (<constant>M</constant> for
+ directories). Those respectively indicate access, creation, last status change, and last modification
+ time of a file system entry. The lower-case letter signifies that the given timestamp type should be
+ considered for files, while the upper-case letter signifies that the given timestamp type should be
+ considered for directories. See <citerefentry
+ project='man-pages'><refentrytitle>statx</refentrytitle><manvolnum>2</manvolnum></citerefentry> file
+ timestamp fields for more details about timestamp types.</para>
+
+ <para>If not specified, the age-by field defaults to <constant>abcmABM</constant>, i.e. by default all
+ file timestamps are taken into consideration, with the exception of the last status change timestamp
+ (ctime) for directories. This is because the aging logic itself will alter the ctime whenever it
+ deletes a file inside it. To ensure that running the aging logic does not feed back into the next
+ iteration of itself, ctime for directories is ignored by default.</para>
+
+ <para>For example:<programlisting>
+# Files created and modified, and directories accessed more than
+# an hour ago in "/tmp/foo/bar", are subject to time-based cleanup.
+d /tmp/foo/bar - - - bmA:1h -</programlisting></para>
+
+ <para>Note that while the aging algorithm is run a 'shared' BSD file lock (see <citerefentry
+ project='man-pages'><refentrytitle>flock</refentrytitle><manvolnum>2</manvolnum></citerefentry>) is
+ taken on each directory the algorithm descends into (and each directory below that, and so on). If the
+ aging algorithm finds a lock is already taken on some directory, it (and everything below it) is
+ skipped. Applications may use this to temporarily exclude certain directory subtrees from the aging
+ algorithm: the applications can take a BSD file lock themselves, and as long as they keep it aging of
+ the directory and everything below it is disabled.</para>
+ </refsect2>
+
+ <refsect2>
+ <title>Argument</title>
+
+ <para>For <varname>L</varname> lines determines the destination path of the symlink. For <varname>c</varname> and
+ <varname>b</varname>, determines the major/minor of the device node, with major and minor formatted as integers,
+ separated by <literal>:</literal>, e.g. <literal>1:3</literal>. For <varname>f</varname>, <varname>F</varname>,
+ and <varname>w</varname>, the argument may be used to specify a short string that is written to the file,
+ suffixed by a newline. For <varname>C</varname>, specifies the source file or directory. For <varname>t</varname>
+ and <varname>T</varname>, determines extended attributes to be set. For <varname>a</varname> and
+ <varname>A</varname>, determines ACL attributes to be set. For <varname>h</varname> and <varname>H</varname>,
+ determines the file attributes to set. Ignored for all other lines.</para>
+
+ <para>This field can contain specifiers, see below.</para>
+ </refsect2>
+ </refsect1>
+
+ <refsect1>
+ <title>Specifiers</title>
+
+ <para>Specifiers can be used in the "path" and "argument" fields.
+ An unknown or unresolvable specifier is treated as invalid configuration.
+ The following expansions are understood:</para>
+ <table class='specifiers'>
+ <title>Specifiers available</title>
+ <tgroup cols='3' align='left' colsep='1' rowsep='1'>
+ <colspec colname="spec" />
+ <colspec colname="mean" />
+ <colspec colname="detail" />
+ <thead>
+ <row>
+ <entry>Specifier</entry>
+ <entry>Meaning</entry>
+ <entry>Details</entry>
+ </row>
+ </thead>
+ <tbody>
+ <xi:include href="standard-specifiers.xml" xpointer="a"/>
+ <xi:include href="standard-specifiers.xml" xpointer="A"/>
+ <xi:include href="standard-specifiers.xml" xpointer="b"/>
+ <xi:include href="standard-specifiers.xml" xpointer="B"/>
+ <row>
+ <entry><literal>%C</literal></entry>
+ <entry>System or user cache directory</entry>
+ <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_CACHE_HOME</varname>, and <filename>/var/cache</filename> otherwise.</entry>
+ </row>
+ <row>
+ <entry><literal>%g</literal></entry>
+ <entry>User group</entry>
+ <entry>This is the name of the group running the command. In case of the system instance this resolves to <literal>root</literal>.</entry>
+ </row>
+ <row>
+ <entry><literal>%G</literal></entry>
+ <entry>User GID</entry>
+ <entry>This is the numeric GID of the group running the command. In case of the system instance this resolves to <constant>0</constant>.</entry>
+ </row>
+ <row>
+ <entry><literal>%h</literal></entry>
+ <entry>User home directory</entry>
+ <entry>This is the home directory of the user running the command. In case of the system instance this resolves to <literal>/root</literal>.</entry>
+ </row>
+ <xi:include href="standard-specifiers.xml" xpointer="H"/>
+ <xi:include href="standard-specifiers.xml" xpointer="l"/>
+ <row>
+ <entry><literal>%L</literal></entry>
+ <entry>System or user log directory</entry>
+ <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_CONFIG_HOME</varname> with <filename index="false">/log</filename> appended, and <filename>/var/log</filename> otherwise.</entry>
+ </row>
+ <xi:include href="standard-specifiers.xml" xpointer="m"/>
+ <xi:include href="standard-specifiers.xml" xpointer="M"/>
+ <xi:include href="standard-specifiers.xml" xpointer="o"/>
+ <row>
+ <entry><literal>%S</literal></entry>
+ <entry>System or user state directory</entry>
+ <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_CONFIG_HOME</varname>, and <filename>/var/lib</filename> otherwise.</entry>
+ </row>
+ <row>
+ <entry><literal>%t</literal></entry>
+ <entry>System or user runtime directory</entry>
+ <entry>In <option>--user</option> mode, this is the same <varname>$XDG_RUNTIME_DIR</varname>, and <filename>/run/</filename> otherwise.</entry>
+ </row>
+ <xi:include href="standard-specifiers.xml" xpointer="T"/>
+ <row>
+ <entry><literal>%u</literal></entry>
+ <entry>User name</entry>
+ <entry>This is the name of the user running the command. In case of the system instance this resolves to <literal>root</literal>.</entry>
+ </row>
+ <row>
+ <entry><literal>%U</literal></entry>
+ <entry>User UID</entry>
+ <entry>This is the numeric UID of the user running the command. In case of the system instance this resolves to <constant>0</constant>.</entry>
+ </row>
+ <xi:include href="standard-specifiers.xml" xpointer="v"/>
+ <xi:include href="standard-specifiers.xml" xpointer="V"/>
+ <xi:include href="standard-specifiers.xml" xpointer="w"/>
+ <xi:include href="standard-specifiers.xml" xpointer="W"/>
+ <xi:include href="standard-specifiers.xml" xpointer="percent"/>
+ </tbody>
+ </tgroup>
+ </table>
+ </refsect1>
+
+ <refsect1>
+ <title>Examples</title>
+ <example>
+ <title>Create directories with specific mode and ownership</title>
+ <para>
+ <citerefentry project='die-net'><refentrytitle>screen</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ needs two directories created at boot with specific modes and ownership:</para>
+
+ <programlisting># /usr/lib/tmpfiles.d/screen.conf
+d /run/screens 1777 root screen 10d
+d /run/uscreens 0755 root screen 10d12h
+</programlisting>
+
+ <para>Contents of <filename>/run/screens</filename> and /run/uscreens will
+ be cleaned up after 10 and 10½ days, respectively.</para>
+ </example>
+
+ <example>
+ <title>Create a directory with a SMACK attribute</title>
+ <programlisting>D /run/cups - - - -
+t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar"
+ </programlisting>
+
+ <para>The directory will be owned by root and have default mode. Its contents are
+ not subject to time-based cleanup, but will be obliterated when
+ <command>systemd-tmpfiles --remove</command> runs.</para>
+ </example>
+
+ <example>
+ <title>Create a directory and prevent its contents from cleanup</title>
+ <para>
+ <citerefentry project='die-net'><refentrytitle>abrt</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ needs a directory created at boot with specific mode and ownership and its content
+ should be preserved from the automatic cleanup applied to the contents of
+ <filename>/var/tmp</filename>:</para>
+
+ <programlisting># /usr/lib/tmpfiles.d/tmp.conf
+d /var/tmp 1777 root root 30d
+</programlisting>
+
+ <programlisting># /usr/lib/tmpfiles.d/abrt.conf
+d /var/tmp/abrt 0755 abrt abrt -
+</programlisting>
+ </example>
+
+ <example>
+ <title>Apply clean up during boot and based on time</title>
+
+ <programlisting># /usr/lib/tmpfiles.d/dnf.conf
+r! /var/cache/dnf/*/*/download_lock.pid
+r! /var/cache/dnf/*/*/metadata_lock.pid
+r! /var/lib/dnf/rpmdb_lock.pid
+e /var/cache/dnf/ - - - 30d
+</programlisting>
+
+ <para>The lock files will be removed during boot. Any files and directories in
+ <filename>/var/cache/dnf/</filename> will be removed after they have not been
+ accessed in 30 days.</para>
+ </example>
+
+ <example>
+ <title>Empty the contents of a cache directory on boot</title>
+
+ <programlisting># /usr/lib/tmpfiles.d/krb5rcache.conf
+e! /var/cache/krb5rcache - - - 0
+</programlisting>
+
+ <para>Any files and subdirectories in <filename>/var/cache/krb5rcache/</filename>
+ will be removed on boot. The directory will not be created.
+ </para>
+ </example>
+
+ <example>
+ <title>Provision SSH public key access for root user via Credentials in QEMU</title>
+
+ <programlisting>-smbios type=11,value=io.systemd.credential.binary:tmpfiles.extra=$(echo "f~ /root/.ssh/authorized_keys 700 root root - $(ssh-add -L | base64 -w 0)" | base64 -w 0)
+</programlisting>
+
+ <para>By passing this line to QEMU, the public key of the current user will be encoded in
+ base64, added to a tmpfiles.d line that tells systemd-tmpfiles to decode it into
+ <filename>/root/.ssh/authorized_keys</filename>, encode that line itself in base64 and
+ pass it as a Credential that will be picked up by systemd from SMBIOS on boot.
+ </para>
+ </example>
+ </refsect1>
+
+ <refsect1>
+ <title><filename>/run/</filename> and <filename>/var/run/</filename></title>
+ <para><filename>/var/run/</filename> is a deprecated symlink to <filename>/run/</filename>, and
+ applications should use the latter. <command>systemd-tmpfiles</command> will warn if
+ <filename>/var/run/</filename> is used.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>attr</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>getfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>setfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>setfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>getfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>btrfs-subvolume</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry project='die-net'><refentrytitle>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>