1<?xml version='1.0'?>
2<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4<!--
5  SPDX-License-Identifier: LGPL-2.1-or-later
6
7  Copyright © 2010 Brandon Philips
8-->
9<refentry id="tmpfiles.d"
10          xmlns:xi="http://www.w3.org/2001/XInclude">
11
12  <refentryinfo>
13    <title>tmpfiles.d</title>
14    <productname>systemd</productname>
15  </refentryinfo>
16
17  <refmeta>
18    <refentrytitle>tmpfiles.d</refentrytitle>
19    <manvolnum>5</manvolnum>
20  </refmeta>
21
22  <refnamediv>
23    <refname>tmpfiles.d</refname>
24    <refpurpose>Configuration for creation, deletion and cleaning of
25    volatile and temporary files</refpurpose>
26  </refnamediv>
27
28  <refsynopsisdiv>
29    <para><literallayout><filename>/etc/tmpfiles.d/*.conf</filename>
30<filename>/run/tmpfiles.d/*.conf</filename>
31<filename>/usr/lib/tmpfiles.d/*.conf</filename>
32    </literallayout></para>
33
34    <para><literallayout><filename>~/.config/user-tmpfiles.d/*.conf</filename>
35<filename>$XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf</filename>
36<filename>~/.local/share/user-tmpfiles.d/*.conf</filename>
37<filename index='false'>…</filename>
38<filename>/usr/share/user-tmpfiles.d/*.conf</filename>
39    </literallayout></para>
40
41    <programlisting>#Type Path                                     Mode User Group Age         Argument
42f     /file/to/create                          mode user group -           content
43f+    /file/to/create-or-truncate              mode user group -           content
44w     /file/to/write-to                        -    -    -     -           content
45w+    /file/to/append-to                       -    -    -     -           content
46d     /directory/to/create-and-cleanup         mode user group cleanup-age -
47D     /directory/to/create-and-remove          mode user group cleanup-age -
48e     /directory/to/cleanup                    mode user group cleanup-age -
49v     /subvolume-or-directory/to/create        mode user group cleanup-age -
50q     /subvolume-or-directory/to/create        mode user group cleanup-age -
51Q     /subvolume-or-directory/to/create        mode user group cleanup-age -
52p     /fifo/to/create                          mode user group -           -
53p+    /fifo/to/[re]create                      mode user group -           -
54L     /symlink/to/create                       -    -    -     -           symlink/target/path
55L+    /symlink/to/[re]create                   -    -    -     -           symlink/target/path
56c     /dev/char-device-to-create               mode user group -           major:minor
57c+    /dev/char-device-to-[re]create           mode user group -           major:minor
58b     /dev/block-device-to-create              mode user group -           major:minor
59b+    /dev/block-device-to-[re]create          mode user group -           major:minor
60C     /target/to/create                        -    -    -     cleanup-age /source/to/copy
61x     /path-or-glob/to/ignore/recursively      -    -    -     cleanup-age -
62X     /path-or-glob/to/ignore                  -    -    -     cleanup-age -
63r     /empty/dir/to/remove                     -    -    -     -           -
64R     /dir/to/remove/recursively               -    -    -     -           -
65z     /path-or-glob/to/adjust/mode             mode user group -           -
66Z     /path-or-glob/to/adjust/mode/recursively mode user group -           -
67t     /path-or-glob/to/set/xattrs              -    -    -     -           xattrs
68T     /path-or-glob/to/set/xattrs/recursively  -    -    -     -           xattrs
69h     /path-or-glob/to/set/attrs               -    -    -     -           file attrs
70H     /path-or-glob/to/set/attrs/recursively   -    -    -     -           file attrs
71a     /path-or-glob/to/set/acls                -    -    -     -           POSIX ACLs
72a+    /path-or-glob/to/append/acls             -    -    -     -           POSIX ACLs
73A     /path-or-glob/to/set/acls/recursively    -    -    -     -           POSIX ACLs
74A+    /path-or-glob/to/append/acls/recursively -    -    -     -           POSIX ACLs
75
76</programlisting>
77  </refsynopsisdiv>
78
79  <refsect1>
80    <title>Description</title>
81
82    <para><filename>tmpfiles.d</filename> configuration files provide a generic mechanism to define the
83    <emphasis>creation</emphasis> of regular files, directories, pipes, and device nodes, adjustments to
84    their <emphasis>access mode, ownership, attributes, quota assignments, and contents</emphasis>, and
85    finally their time-based <emphasis>removal</emphasis>. It is mostly commonly used for volatile and
86    temporary files and directories (such as those located under <filename>/run/</filename>,
87    <filename>/tmp/</filename>, <filename>/var/tmp/</filename>, the API file systems such as
88    <filename>/sys/</filename> or <filename>/proc/</filename>, as well as some other directories below
89    <filename>/var/</filename>).</para>
90
91    <para><command>systemd-tmpfiles</command> uses this configuration to create volatile files and
92    directories during boot and to do periodic cleanup afterwards. See
93    <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
94    the description of <filename>systemd-tmpfiles-setup.service</filename>,
95    <filename>systemd-tmpfiles-clean.service</filename>, and associated units.</para>
96
97    <para>System daemons frequently require private runtime directories below <filename>/run/</filename> to
98    store communication sockets and similar. For these, it is better to use
99    <varname>RuntimeDirectory=</varname> in their unit files (see
100    <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
101    details), if the flexibility provided by <filename>tmpfiles.d</filename> is not required. The advantages
102    are that the configuration required by the unit is centralized in one place, and that the lifetime of the
103    directory is tied to the lifetime of the service itself. Similarly, <varname>StateDirectory=</varname>,
104    <varname>CacheDirectory=</varname>, <varname>LogsDirectory=</varname>, and
105    <varname>ConfigurationDirectory=</varname> should be used to create directories under
106    <filename>/var/lib/</filename>, <filename>/var/cache/</filename>, <filename>/var/log/</filename>, and
107    <filename>/etc/</filename>. <filename>tmpfiles.d</filename> should be used for files whose lifetime is
108    independent of any service or requires more complicated configuration.</para>
109  </refsect1>
110
111  <refsect1>
112    <title>Configuration Directories and Precedence</title>
113
114    <para>Each configuration file shall be named in the style of
115    <filename><replaceable>package</replaceable>.conf</filename> or
116    <filename><replaceable>package</replaceable>-<replaceable>part</replaceable>.conf</filename>.
117    The second variant should be used when it is desirable to make it
118    easy to override just this part of configuration.</para>
119
120    <para>Files in <filename>/etc/tmpfiles.d</filename> override files with the same name in
121    <filename>/usr/lib/tmpfiles.d</filename> and <filename>/run/tmpfiles.d</filename>. Files in
122    <filename>/run/tmpfiles.d</filename> override files with the same name in
123    <filename>/usr/lib/tmpfiles.d</filename>. Packages should install their configuration files in
124    <filename>/usr/lib/tmpfiles.d</filename>. Files in <filename>/etc/tmpfiles.d</filename> are reserved for
125    the local administrator, who may use this logic to override the configuration files installed by vendor
126    packages. All configuration files are sorted by their filename in lexicographic order, regardless of
127    which of the directories they reside in. If multiple files specify the same path, the entry in the file
128    with the lexicographically earliest name will be applied (note that lines suppressed due to the
129    <literal>!</literal> are filtered before application, meaning that if an early line carries the
130    exclamation mark and is suppressed because of that, a later line matching in path will be applied).  All
131    other conflicting entries will be logged as errors. When two lines are prefix path and suffix path of
132    each other, then the prefix line is always created first, the suffix later (and if removal applies to the
133    line, the order is reversed: the suffix is removed first, the prefix later). Lines that take globs are
134    applied after those accepting no globs. If multiple operations shall be applied on the same file (such as
135    ACL, xattr, file attribute adjustments), these are always done in the same fixed order. Except for those
136    cases, the files/directories are processed in the order they are listed.</para>
137
138    <para>If the administrator wants to disable a configuration file
139    supplied by the vendor, the recommended way is to place a symlink
140    to <filename>/dev/null</filename> in
141    <filename>/etc/tmpfiles.d/</filename> bearing the same filename.
142    </para>
143  </refsect1>
144
145  <refsect1>
146    <title>Configuration File Format</title>
147
148    <para>The configuration format is one line per path, containing type, path, mode, ownership, age, and
149    argument fields. The lines are separated by newlines, the fields by whitespace:</para>
150
151    <programlisting>#Type Path        Mode User Group Age Argument…
152d     /run/user   0755 root root  10d -
153L     /tmp/foobar -    -    -     -   /dev/null</programlisting>
154
155    <para>Fields may contain C-style escapes. With the exception of the seventh field (the "argument") all
156    fields may be enclosed in quotes. Note that any whitespace found in the line after the beginning of the
157    argument field will be considered part of the argument field. To begin the argument field with a
158    whitespace character, use C-style escapes (e.g. <literal>\x20</literal>).</para>
159
160    <refsect2>
161      <title>Type</title>
162
163      <para>The type consists of a single letter and optionally an exclamation mark (<literal>!</literal>)
164      minus sign (<literal>-</literal>), and/or equals sign (<literal>=</literal>).</para>
165
166      <para>The following line types are understood:</para>
167
168      <variablelist>
169        <varlistentry>
170          <term><varname>f</varname></term>
171          <term><varname>f+</varname></term>
172          <listitem><para><varname>f</varname> will create a file if it does not exist yet. If the argument
173          parameter is given and the file did not exist yet, it will be written to the file.
174          <varname>f+</varname> will create or truncate the file. If the argument parameter is given, it will
175          be written to the file. Does not follow symlinks.</para></listitem>
176        </varlistentry>
177
178        <varlistentry>
179          <term><varname>w</varname></term>
180          <term><varname>w+</varname></term>
181          <listitem><para>Write the argument parameter to a file, if the file exists.
182          If suffixed with <varname>+</varname>, the line will be appended to the file.
183          If your configuration writes multiple lines to the same file, use <varname>w+</varname>.
184          Lines of this type accept shell-style globs in place of normal path names.
185          The argument parameter will be written without a trailing newline.
186          C-style backslash escapes are interpreted. Follows symlinks.</para></listitem>
187        </varlistentry>
188
189        <varlistentry>
190          <term><varname>d</varname></term>
191          <listitem><para>Create a directory. The mode and ownership will be adjusted if specified. Contents
192          of this directory are subject to time based cleanup if the age argument is specified.
193          </para></listitem>
194        </varlistentry>
195
196        <varlistentry>
197          <term><varname>D</varname></term>
198          <listitem><para>Similar to <varname>d</varname>, but in addition the contents of the directory will
199          be removed when <option>--remove</option> is used.</para></listitem>
200        </varlistentry>
201
202        <varlistentry>
203          <term><varname>e</varname></term>
204          <listitem><para>Adjust the mode and ownership of existing directories and remove their contents
205          based on age.
206          Lines of this type accept shell-style globs in place of normal path names. Contents of the
207          directories are subject to time based cleanup if the age argument is specified. If the age argument
208          is <literal>0</literal>, contents will be unconditionally deleted every time
209          <command>systemd-tmpfiles --clean</command> is run.</para>
210
211          <para>For this entry to be useful, at least one of the mode, user, group, or age arguments must be
212          specified, since otherwise this entry has no effect. As an exception, an entry with no effect may
213          be useful when combined with <varname>!</varname>, see the examples.</para></listitem>
214        </varlistentry>
215
216        <varlistentry>
217          <term><varname>v</varname></term>
218          <listitem><para>Create a subvolume if the path does not exist yet, the file system supports
219          subvolumes (btrfs), and the system itself is installed into a subvolume (specifically: the root
220          directory <filename>/</filename> is itself a subvolume). Otherwise, create a normal directory, in
221          the same way as <varname>d</varname>.</para>
222
223          <para>A subvolume created with this line type is not assigned to any higher-level quota group. For
224          that, use <varname>q</varname> or <varname>Q</varname>, which allow creating simple quota group
225          hierarchies, see below.</para></listitem>
226        </varlistentry>
227
228        <varlistentry>
229          <term><varname>q</varname></term>
230          <listitem><para>Create a subvolume or directory the same as <varname>v</varname>, but assign the
231          subvolume to the same higher-level quota groups as the parent. This ensures that higher-level
232          limits and accounting applied to the parent subvolume also include the specified subvolume. On
233          non-btrfs file systems, this line type is identical to <varname>d</varname>.</para>
234
235          <para>If the subvolume already exists, no change to the quota hierarchy is made, regardless of whether the
236          subvolume is already attached to a quota group or not. Also see <varname>Q</varname> below. See <citerefentry
237          project='die-net'><refentrytitle>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
238          details about the btrfs quota group concept.</para></listitem>
239        </varlistentry>
240
241        <varlistentry>
242          <term><varname>Q</varname></term>
243          <listitem><para>Create the subvolume or directory the same as <varname>v</varname>, but assign the
244          new subvolume to a new leaf quota group. Instead of copying the higher-level quota group
245          assignments from the parent as is done with <varname>q</varname>, the lowest quota group of the
246          parent subvolume is determined that is not the leaf quota group. Then, an "intermediary" quota
247          group is inserted that is one level below this level, and shares the same ID part as the specified
248          subvolume. If no higher-level quota group exists for the parent subvolume, a new quota group at
249          level 255 sharing the same ID as the specified subvolume is inserted instead. This new intermediary
250          quota group is then assigned to the parent subvolume's higher-level quota groups, and the specified
251          subvolume's leaf quota group is assigned to it.</para>
252
253          <para>Effectively, this has a similar effect as <varname>q</varname>, however introduces a new higher-level
254          quota group for the specified subvolume that may be used to enforce limits and accounting to the specified
255          subvolume and children subvolume created within it. Thus, by creating subvolumes only via
256          <varname>q</varname> and <varname>Q</varname>, a concept of "subtree quotas" is implemented. Each subvolume
257          for which <varname>Q</varname> is set will get a "subtree" quota group created, and all child subvolumes
258          created within it will be assigned to it. Each subvolume for which <varname>q</varname> is set will not get
259          such a "subtree" quota group, but it is ensured that they are added to the same "subtree" quota group as
260          their immediate parents.</para>
261
262          <para>It is recommended to use <varname>Q</varname> for subvolumes that typically contain further subvolumes,
263          and where it is desirable to have accounting and quota limits on all child subvolumes together. Examples for
264          <varname>Q</varname> are typically <filename>/home/</filename> or <filename>/var/lib/machines/</filename>. In
265          contrast, <varname>q</varname> should be used for subvolumes that either usually do not include further
266          subvolumes or where no accounting and quota limits are needed that apply to all child subvolumes
267          together. Examples for <varname>q</varname> are typically <filename>/var/</filename> or
268          <filename>/var/tmp/</filename>. </para>
269
270          <para>As with <varname>q</varname>, <varname>Q</varname> has no effect on the quota group hierarchy if the
271          subvolume already exists, regardless of whether the subvolume already belong to a quota group or not.
272          </para></listitem>
273        </varlistentry>
274
275        <varlistentry>
276          <term><varname>p</varname></term>
277          <term><varname>p+</varname></term>
278          <listitem><para>Create a named pipe (FIFO) if it does not
279          exist yet. If suffixed with <varname>+</varname> and a file
280          already exists where the pipe is to be created, it will be
281          removed and be replaced by the pipe.</para></listitem>
282        </varlistentry>
283
284        <varlistentry>
285          <term><varname>L</varname></term>
286          <term><varname>L+</varname></term>
287          <listitem><para>Create a symlink if it does not exist
288          yet. If suffixed with <varname>+</varname> and a file or
289          directory already exists where the symlink is to be created,
290          it will be removed and be replaced by the symlink. If the
291          argument is omitted, symlinks to files with the same name
292          residing in the directory
293          <filename>/usr/share/factory/</filename> are created. Note
294          that permissions and ownership on symlinks are ignored.
295          </para></listitem>
296        </varlistentry>
297
298        <varlistentry>
299          <term><varname>c</varname></term>
300          <term><varname>c+</varname></term>
301          <listitem><para>Create a character device node if it does
302          not exist yet. If suffixed with <varname>+</varname> and a
303          file already exists where the device node is to be created,
304          it will be removed and be replaced by the device node. It is
305          recommended to suffix this entry with an exclamation mark to
306          only create static device nodes at boot, as udev will not
307          manage static device nodes that are created at runtime.
308          </para></listitem>
309        </varlistentry>
310
311        <varlistentry>
312          <term><varname>b</varname></term>
313          <term><varname>b+</varname></term>
314          <listitem><para>Create a block device node if it does not
315          exist yet. If suffixed with <varname>+</varname> and a file
316          already exists where the device node is to be created, it
317          will be removed and be replaced by the device node. It is
318          recommended to suffix this entry with an exclamation mark to
319          only create static device nodes at boot, as udev will not
320          manage static device nodes that are created at runtime.
321          </para></listitem>
322        </varlistentry>
323
324        <varlistentry>
325          <term><varname>C</varname></term>
326          <listitem><para>Recursively copy a file or directory, if the
327          destination files or directories do not exist yet or the
328          destination directory is empty. Note that this command will not
329          descend into subdirectories if the destination directory already
330          exists and is not empty. Instead, the entire copy operation is
331          skipped. If the argument is omitted, files from the source directory
332          <filename>/usr/share/factory/</filename> with the same name
333          are copied. Does not follow symlinks. Contents of the directories
334          are subject to time based cleanup if the age argument is specified.
335          </para></listitem>
336        </varlistentry>
337
338        <varlistentry>
339          <term><varname>x</varname></term>
340          <listitem><para>Ignore a path during cleaning. Use this type
341          to exclude paths from clean-up as controlled with the Age
342          parameter. Note that lines of this type do not influence the
343          effect of <varname>r</varname> or <varname>R</varname>
344          lines. Lines of this type accept shell-style globs in place
345          of normal path names.  </para></listitem>
346        </varlistentry>
347
348        <varlistentry>
349          <term><varname>X</varname></term>
350          <listitem><para>Ignore a path during cleaning. Use this type
351          to exclude paths from clean-up as controlled with the Age
352          parameter. Unlike <varname>x</varname>, this parameter will
353          not exclude the content if path is a directory, but only
354          directory itself. Note that lines of this type do not
355          influence the effect of <varname>r</varname> or
356          <varname>R</varname> lines. Lines of this type accept
357          shell-style globs in place of normal path names.
358          </para></listitem>
359        </varlistentry>
360
361        <varlistentry>
362          <term><varname>r</varname></term>
363          <listitem><para>Remove a file or directory if it exists.
364          This may not be used to remove non-empty directories, use
365          <varname>R</varname> for that.  Lines of this type accept
366          shell-style globs in place of normal path
367          names. Does not follow symlinks.</para></listitem>
368        </varlistentry>
369
370        <varlistentry>
371          <term><varname>R</varname></term>
372          <listitem><para>Recursively remove a path and all its
373          subdirectories (if it is a directory). Lines of this type
374          accept shell-style globs in place of normal path
375          names. Does not follow symlinks.</para></listitem>
376        </varlistentry>
377
378        <varlistentry>
379          <term><varname>z</varname></term>
380          <listitem><para>Adjust the access mode, user and group ownership, and restore the SELinux security
381          context of a file or directory, if it exists. Lines of this type accept shell-style globs in place
382          of normal path names. Does not follow symlinks.</para></listitem>
383        </varlistentry>
384
385        <varlistentry>
386          <term><varname>Z</varname></term>
387          <listitem><para>Recursively set the access mode, user and group ownership, and restore the SELinux
388          security context of a file or directory if it exists, as well as of its subdirectories and the
389          files contained therein (if applicable). Lines of this type accept shell-style globs in place of
390          normal path names. Does not follow symlinks.</para></listitem>
391        </varlistentry>
392
393        <varlistentry>
394          <term><varname>t</varname></term>
395          <listitem><para>Set extended attributes, see <citerefentry
396          project='man-pages'><refentrytitle>attr</refentrytitle>
397          <manvolnum>5</manvolnum></citerefentry> for details. The argument field should take one or more
398          assignment expressions in the form
399          <replaceable>namespace</replaceable>.<replaceable>attribute</replaceable>=<replaceable>value</replaceable>,
400          for examples see below. Lines of this type accept shell-style globs in place of normal path
401          names. This can be useful for setting SMACK labels. Does not follow symlinks.</para>
402
403          <para>Please note that extended attributes settable with this line type are a different concept
404          from the Linux file attributes settable with <varname>h</varname>/<varname>H</varname>, see
405          below.</para></listitem>
406        </varlistentry>
407
408        <varlistentry>
409          <term><varname>T</varname></term>
410          <listitem><para>Same as <varname>t</varname>, but operates recursively.</para></listitem>
411        </varlistentry>
412
413        <varlistentry>
414          <term><varname>h</varname></term>
415          <listitem><para>Set Linux file/directory attributes. Lines of this type accept shell-style globs in
416          place of normal path names.</para>
417
418          <para>The format of the argument field is <varname>[+-=][aAcCdDeijPsStTu]</varname>. The prefix
419          <varname>+</varname> (the default one) causes the attribute(s) to be added; <varname>-</varname>
420          causes the attribute(s) to be removed; <varname>=</varname> causes the attributes to be set exactly
421          as the following letters. The letters <literal>aAcCdDeijPsStTu</literal> select the new attributes
422          for the files, see <citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle>
423          <manvolnum>1</manvolnum></citerefentry> for further information.
424          </para>
425
426          <para>Passing only <varname>=</varname> as argument resets all the file attributes listed above. It
427          has to be pointed out that the <varname>=</varname> prefix limits itself to the attributes
428          corresponding to the letters listed here. All other attributes will be left untouched. Does not
429          follow symlinks.</para>
430
431          <para>Please note that the Linux file attributes settable with this line type are a different
432          concept from the extended attributes settable with <varname>t</varname>/<varname>T</varname>,
433          see above.</para></listitem>
434        </varlistentry>
435
436        <varlistentry>
437          <term><varname>H</varname></term>
438          <listitem><para>Sames as <varname>h</varname>, but operates recursively.</para></listitem>
439        </varlistentry>
440
441        <varlistentry>
442          <term><varname>a</varname></term>
443          <term><varname>a+</varname></term>
444          <listitem><para>Set POSIX ACLs (access control lists), see <citerefentry
445          project='man-pages'><refentrytitle>acl</refentrytitle>
446          <manvolnum>5</manvolnum></citerefentry>. If suffixed with <varname>+</varname>, the specified
447          entries will be added to the existing set. <command>systemd-tmpfiles</command> will automatically
448          add the required base entries for user and group based on the access mode of the file, unless base
449          entries already exist or are explicitly specified. The mask will be added if not specified
450          explicitly or already present. Lines of this type accept shell-style globs in place of normal path
451          names. This can be useful for allowing additional access to certain files. Does not follow
452          symlinks.</para></listitem>
453        </varlistentry>
454
455        <varlistentry>
456          <term><varname>A</varname></term>
457          <term><varname>A+</varname></term>
458          <listitem><para>Same as <varname>a</varname> and
459          <varname>a+</varname>, but recursive. Does not follow
460          symlinks.</para></listitem>
461        </varlistentry>
462      </variablelist>
463
464      <para>If the exclamation mark (<literal>!</literal>) is used, this line is only safe to execute during
465      boot, and can break a running system. Lines without the exclamation mark are presumed to be safe to
466      execute at any time, e.g. on package upgrades. <command>systemd-tmpfiles</command> will take lines with
467      an exclamation mark only into consideration, if the <option>--boot</option> option is given.</para>
468
469      <para>For example:
470      <programlisting># Make sure these are created by default so that nobody else can
471d /tmp/.X11-unix 1777 root root 10d
472
473# Unlink the X11 lock files
474r! /tmp/.X[0-9]*-lock</programlisting>
475      The second line in contrast to the first one would break a
476      running system, and will only be executed with
477      <option>--boot</option>.</para>
478
479      <para>If the minus sign (<literal>-</literal>) is used, this line failing to run successfully during
480      create (and only create) will not cause the execution of <command>systemd-tmpfiles</command> to return
481      an error.</para>
482
483      <para>For example:
484      <programlisting># Modify sysfs but don't fail if we are in a container with a read-only /proc
485w- /proc/sys/vm/swappiness - - - - 10</programlisting></para>
486
487      <para>If the equals sign (<literal>=</literal>) is used, the file types of existing objects in the specified path
488      are checked, and removed if they do not match. This includes any implicitly created parent directories (which can
489      be either directories or directory symlinks). For example, if there is a FIFO in place of one of the parent path
490      components it will be replaced with a directory.</para>
491
492      <para>Note that for all line types that result in creation of any kind of file node
493      (i.e. <varname>f</varname>/<varname>F</varname>,
494      <varname>d</varname>/<varname>D</varname>/<varname>v</varname>/<varname>q</varname>/<varname>Q</varname>,
495      <varname>p</varname>, <varname>L</varname>, <varname>c</varname>/<varname>b</varname> and <varname>C</varname>)
496      leading directories are implicitly created if needed, owned by root with an access mode of 0755. In order to
497      create them with different modes or ownership make sure to add appropriate <varname>d</varname> lines.</para>
498    </refsect2>
499
500    <refsect2>
501      <title>Path</title>
502
503      <para>The file system path specification supports simple
504      specifier expansion, see below. The path (after expansion) must be
505      absolute.</para>
506    </refsect2>
507
508    <refsect2>
509      <title>Mode</title>
510
511      <para>The file access mode to use when creating this file or
512      directory. If omitted or when set to <literal>-</literal>, the
513      default is used: 0755 for directories, 0644 for all other file
514      objects.  For <varname>z</varname>, <varname>Z</varname> lines,
515      if omitted or when set to <literal>-</literal>, the file access
516      mode will not be modified. This parameter is ignored for
517      <varname>x</varname>, <varname>r</varname>,
518      <varname>R</varname>, <varname>L</varname>, <varname>t</varname>,
519      and <varname>a</varname> lines.</para>
520
521      <para>Optionally, if prefixed with <literal>~</literal>, the
522      access mode is masked based on the already set access bits for
523      existing file or directories: if the existing file has all
524      executable bits unset, all executable bits are removed from the
525      new access mode, too. Similarly, if all read bits are removed
526      from the old access mode, they will be removed from the new
527      access mode too, and if all write bits are removed, they will be
528      removed from the new access mode too. In addition, the
529      sticky/SUID/SGID bit is removed unless applied to a
530      directory. This functionality is particularly useful in
531      conjunction with <varname>Z</varname>.</para>
532    </refsect2>
533
534    <refsect2>
535      <title>User, Group</title>
536
537      <para>The user and group to use for this file or directory. This may either be a numeric ID or a
538      user/group name. If omitted or when set to <literal>-</literal>, the user and group of the user who
539      invokes <command>systemd-tmpfiles</command> is used. For <varname>z</varname> and <varname>Z</varname>
540      lines, when omitted or when set to <literal>-</literal>, the file ownership will not be modified. These
541      parameters are ignored for <varname>x</varname>, <varname>r</varname>, <varname>R</varname>,
542      <varname>L</varname>, <varname>t</varname>, and <varname>a</varname> lines.</para>
543
544      <para>This field should generally only reference system users/groups, i.e. users/groups that are
545      guaranteed to be resolvable during early boot. If this field references users/groups that only become
546      resolveable during later boot (i.e. after NIS, LDAP or a similar networked directory service become
547      available), execution of the operations declared by the line will likely fail. Also see <ulink
548      url="https://systemd.io/UIDS-GIDS/#notes-on-resolvability-of-user-and-group-names">Notes on
549      Resolvability of User and Group Names</ulink> for more information on requirements on system user/group
550      definitions.</para>
551    </refsect2>
552
553    <refsect2>
554      <title>Age</title>
555
556      <para>The date field, when set, is used to decide what files to
557      delete when cleaning. If a file or directory is older than the
558      current time minus the age field, it is deleted. The field
559      format is a series of integers each followed by one of the
560      following suffixes for the respective time units:
561      <constant>s</constant>,
562      <constant>m</constant> or <constant>min</constant>,
563      <constant>h</constant>,
564      <constant>d</constant>,
565      <constant>w</constant>,
566      <constant>ms</constant>, and
567      <constant>us</constant>,
568      meaning seconds, minutes, hours, days, weeks,
569      milliseconds, and microseconds, respectively. Full names of the time units can
570      be used too.
571      </para>
572
573      <para>If multiple integers and units are specified, the time
574      values are summed. If an integer is given without a unit,
575      <constant>s</constant> is assumed.
576      </para>
577
578      <para>When the age is set to zero, the files are cleaned
579      unconditionally.</para>
580
581      <para>The age field only applies to lines starting with
582      <varname>d</varname>, <varname>D</varname>, <varname>e</varname>,
583      <varname>v</varname>, <varname>q</varname>,
584      <varname>Q</varname>, <varname>C</varname>, <varname>x</varname>
585      and <varname>X</varname>. If omitted or set to
586      <literal>-</literal>, no automatic clean-up is done.</para>
587
588      <para>If the age field starts with a tilde character <literal>~</literal>, clean-up is only applied to
589      files and directories one level inside the directory specified, but not the files and directories
590      immediately inside it.</para>
591
592      <para>The age of a file system entry is determined from its last
593      modification timestamp (mtime), its last access timestamp (atime),
594      and (except for directories) its last status change timestamp
595      (ctime). By default, any of these three (or two) values will
596      prevent cleanup if it is more recent than the current time minus
597      the age field. To restrict the deletion based on particular type
598      of file timestamps, the age-by argument can be used.</para>
599
600      <para>The age-by argument overrides the timestamp types to be used for the age check. It can be
601      specified by prefixing the age argument with a sequence of characters to specify the timestamp types
602      and a colon (<literal>:</literal>):
603      <literal><replaceable>age-by</replaceable>...:<replaceable>cleanup-age</replaceable></literal>.  The
604      argument can consist of <constant>a</constant> (<constant>A</constant> for directories),
605      <constant>b</constant> (<constant>B</constant> for directories), <constant>c</constant>
606      (<constant>C</constant> for directories), or <constant>m</constant> (<constant>M</constant> for
607      directories). Those respectively indicate access, creation, last status change, and last modification
608      time of a file system entry. The lower-case letter signifies that the given timestamp type should be
609      considered for files, while the upper-case letter signifies that the given timestamp type should be
610      considered for directories. See <citerefentry
611      project='man-pages'><refentrytitle>statx</refentrytitle><manvolnum>2</manvolnum></citerefentry> file
612      timestamp fields for more details about timestamp types.</para>
613
614      <para>If not specified, the age-by field defaults to <constant>abcmABM</constant>, i.e. by default all
615      file timestamps are taken into consideration, with the exception of the last status change timestamp
616      (ctime) for directories. This is because the aging logic itself will alter the ctime whenever it
617      deletes a file inside it. To ensure that running the aging logic does not feed back into the next
618      iteration of itself, ctime for directories is ignored by default.</para>
619
620      <para>For example:<programlisting>
621# Files created and modified, and directories accessed more than
622# an hour ago in "/tmp/foo/bar", are subject to time-based cleanup.
623d /tmp/foo/bar - - - - bmA:1h -</programlisting></para>
624
625      <para>Note that while the aging algorithm is run a 'shared' BSD file lock (see <citerefentry
626      project='man-pages'><refentrytitle>flock</refentrytitle><manvolnum>2</manvolnum></citerefentry>) is
627      taken on each directory the algorithm descends into (and each directory below that, and so on). If the
628      aging algorithm finds a lock is already taken on some directory, it (and everything below it) is
629      skipped. Applications may use this to temporarily exclude certain directory subtrees from the aging
630      algorithm: the applications can take a BSD file lock themselves, and as long as they keep it aging of
631      the directory and everything below it is disabled.</para>
632    </refsect2>
633
634    <refsect2>
635      <title>Argument</title>
636
637      <para>For <varname>L</varname> lines determines the destination path of the symlink. For <varname>c</varname> and
638      <varname>b</varname>, determines the major/minor of the device node, with major and minor formatted as integers,
639      separated by <literal>:</literal>, e.g.  <literal>1:3</literal>. For <varname>f</varname>, <varname>F</varname>,
640      and <varname>w</varname>, the argument may be used to specify a short string that is written to the file,
641      suffixed by a newline. For <varname>C</varname>, specifies the source file or directory. For <varname>t</varname>
642      and <varname>T</varname>, determines extended attributes to be set. For <varname>a</varname> and
643      <varname>A</varname>, determines ACL attributes to be set. For <varname>h</varname> and <varname>H</varname>,
644      determines the file attributes to set. Ignored for all other lines.</para>
645
646      <para>This field can contain specifiers, see below.</para>
647    </refsect2>
648  </refsect1>
649
650  <refsect1>
651    <title>Specifiers</title>
652
653    <para>Specifiers can be used in the "path" and "argument" fields.
654    An unknown or unresolvable specifier is treated as invalid configuration.
655    The following expansions are understood:</para>
656      <table class='specifiers'>
657        <title>Specifiers available</title>
658        <tgroup cols='3' align='left' colsep='1' rowsep='1'>
659          <colspec colname="spec" />
660          <colspec colname="mean" />
661          <colspec colname="detail" />
662          <thead>
663            <row>
664              <entry>Specifier</entry>
665              <entry>Meaning</entry>
666              <entry>Details</entry>
667            </row>
668          </thead>
669          <tbody>
670            <xi:include href="standard-specifiers.xml" xpointer="a"/>
671            <xi:include href="standard-specifiers.xml" xpointer="A"/>
672            <xi:include href="standard-specifiers.xml" xpointer="b"/>
673            <xi:include href="standard-specifiers.xml" xpointer="B"/>
674            <row>
675              <entry><literal>%C</literal></entry>
676              <entry>System or user cache directory</entry>
677              <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_CACHE_HOME</varname>, and <filename>/var/cache</filename> otherwise.</entry>
678            </row>
679            <row>
680              <entry><literal>%g</literal></entry>
681              <entry>User group</entry>
682              <entry>This is the name of the group running the command. In case of the system instance this resolves to <literal>root</literal>.</entry>
683            </row>
684            <row>
685              <entry><literal>%G</literal></entry>
686              <entry>User GID</entry>
687              <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>
688            </row>
689            <row>
690              <entry><literal>%h</literal></entry>
691              <entry>User home directory</entry>
692              <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>
693            </row>
694            <xi:include href="standard-specifiers.xml" xpointer="H"/>
695            <xi:include href="standard-specifiers.xml" xpointer="l"/>
696            <row>
697              <entry><literal>%L</literal></entry>
698              <entry>System or user log directory</entry>
699              <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_CONFIG_HOME</varname> with <filename index="false">/log</filename> appended, and <filename>/var/log</filename> otherwise.</entry>
700            </row>
701            <xi:include href="standard-specifiers.xml" xpointer="m"/>
702            <xi:include href="standard-specifiers.xml" xpointer="M"/>
703            <xi:include href="standard-specifiers.xml" xpointer="o"/>
704            <row>
705              <entry><literal>%S</literal></entry>
706              <entry>System or user state directory</entry>
707              <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_CONFIG_HOME</varname>, and <filename>/var/lib</filename> otherwise.</entry>
708            </row>
709            <row>
710              <entry><literal>%t</literal></entry>
711              <entry>System or user runtime directory</entry>
712              <entry>In <option>--user</option> mode, this is the same <varname>$XDG_RUNTIME_DIR</varname>, and <filename>/run/</filename> otherwise.</entry>
713            </row>
714            <xi:include href="standard-specifiers.xml" xpointer="T"/>
715            <row>
716              <entry><literal>%u</literal></entry>
717              <entry>User name</entry>
718              <entry>This is the name of the user running the command. In case of the system instance this resolves to <literal>root</literal>.</entry>
719            </row>
720            <row>
721              <entry><literal>%U</literal></entry>
722              <entry>User UID</entry>
723              <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>
724            </row>
725            <xi:include href="standard-specifiers.xml" xpointer="v"/>
726            <xi:include href="standard-specifiers.xml" xpointer="V"/>
727            <xi:include href="standard-specifiers.xml" xpointer="w"/>
728            <xi:include href="standard-specifiers.xml" xpointer="W"/>
729            <xi:include href="standard-specifiers.xml" xpointer="percent"/>
730          </tbody>
731        </tgroup>
732      </table>
733  </refsect1>
734
735  <refsect1>
736    <title>Examples</title>
737    <example>
738      <title>Create directories with specific mode and ownership</title>
739      <para>
740      <citerefentry project='die-net'><refentrytitle>screen</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
741      needs two directories created at boot with specific modes and ownership:</para>
742
743      <programlisting># /usr/lib/tmpfiles.d/screen.conf
744d /run/screens  1777 root screen 10d
745d /run/uscreens 0755 root screen 10d12h
746</programlisting>
747
748      <para>Contents of <filename>/run/screens</filename> and /run/uscreens will
749      be cleaned up after 10 and 10½ days, respectively.</para>
750    </example>
751
752    <example>
753      <title>Create a directory with a SMACK attribute</title>
754      <programlisting>D /run/cups - - - -
755t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar"
756      </programlisting>
757
758      <para>The directory will be owned by root and have default mode. Its contents are
759      not subject to time based cleanup, but will be obliterated when
760      <command>systemd-tmpfiles --remove</command> runs.</para>
761    </example>
762
763    <example>
764      <title>Create a directory and prevent its contents from cleanup</title>
765      <para>
766      <citerefentry project='die-net'><refentrytitle>abrt</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
767      needs a directory created at boot with specific mode and ownership and its content
768      should be preserved from the automatic cleanup applied to the contents of
769      <filename>/var/tmp</filename>:</para>
770
771      <programlisting># /usr/lib/tmpfiles.d/tmp.conf
772d /var/tmp 1777 root root 30d
773</programlisting>
774
775      <programlisting># /usr/lib/tmpfiles.d/abrt.conf
776d /var/tmp/abrt 0755 abrt abrt -
777</programlisting>
778    </example>
779
780    <example>
781      <title>Apply clean up during boot and based on time</title>
782
783      <programlisting># /usr/lib/tmpfiles.d/dnf.conf
784r! /var/cache/dnf/*/*/download_lock.pid
785r! /var/cache/dnf/*/*/metadata_lock.pid
786r! /var/lib/dnf/rpmdb_lock.pid
787e  /var/cache/dnf/ - - - 30d
788</programlisting>
789
790     <para>The lock files will be removed during boot. Any files and directories in
791     <filename>/var/cache/dnf/</filename> will be removed after they have not been
792     accessed in 30 days.</para>
793    </example>
794
795    <example>
796      <title>Empty the contents of a cache directory on boot</title>
797
798      <programlisting># /usr/lib/tmpfiles.d/krb5rcache.conf
799e! /var/cache/krb5rcache - - - 0
800</programlisting>
801
802      <para>Any files and subdirectories in <filename>/var/cache/krb5rcache/</filename>
803      will be removed on boot. The directory will not be created.
804      </para>
805    </example>
806  </refsect1>
807
808  <refsect1>
809    <title><filename>/run/</filename> and <filename>/var/run/</filename></title>
810    <para><filename>/var/run/</filename> is a deprecated symlink to <filename>/run/</filename>, and
811    applications should use the latter. <command>systemd-tmpfiles</command> will warn if
812    <filename>/var/run/</filename> is used.</para>
813  </refsect1>
814
815  <refsect1>
816    <title>See Also</title>
817    <para>
818      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
819      <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
820      <citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
821      <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
822      <citerefentry project='man-pages'><refentrytitle>attr</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
823      <citerefentry project='man-pages'><refentrytitle>getfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
824      <citerefentry project='man-pages'><refentrytitle>setfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
825      <citerefentry project='man-pages'><refentrytitle>setfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
826      <citerefentry project='man-pages'><refentrytitle>getfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
827      <citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
828      <citerefentry project='die-net'><refentrytitle>btrfs-subvolume</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
829      <citerefentry project='die-net'><refentrytitle>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
830    </para>
831  </refsect1>
832
833</refentry>
834