2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
5 SPDX-License-Identifier: LGPL-2.1+
7 Copyright © 2010 Brandon Philips
9 <refentry id=
"tmpfiles.d">
12 <title>tmpfiles.d
</title>
13 <productname>systemd
</productname>
17 <refentrytitle>tmpfiles.d
</refentrytitle>
18 <manvolnum>5</manvolnum>
22 <refname>tmpfiles.d
</refname>
23 <refpurpose>Configuration for creation, deletion and cleaning of
24 volatile and temporary files
</refpurpose>
28 <para><literallayout><filename>/etc/tmpfiles.d/*.conf
</filename>
29 <filename>/run/tmpfiles.d/*.conf
</filename>
30 <filename>/usr/lib/tmpfiles.d/*.conf
</filename>
31 </literallayout></para>
33 <para><literallayout><filename>~/.config/user-tmpfiles.d/*.conf
</filename>
34 <filename>$XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf
</filename>
35 <filename>~/.local/share/user-tmpfiles.d/*.conf
</filename>
36 <filename>…
</filename>
37 <filename>/usr/share/user-tmpfiles.d/*.conf
</filename>
38 </literallayout></para>
40 <programlisting>#Type Path Mode User Group Age Argument
41 f /file/to/create mode user group - content
42 f+ /file/to/create-or-truncate mode user group - content
43 w /file/to/write-to - - - - content
44 d /directory/to/create-and-cleanup mode user group cleanup-age -
45 D /directory/to/create-and-remove mode user group cleanup-age -
46 e /directory/to/cleanup mode user group cleanup-age -
47 v /subvolume/to/create mode user group - -
48 v /subvolume-or-directory/to/create mode user group - -
49 Q /subvolume/to/create mode user group - -
50 p /fifo/to/create mode user group - -
51 L /symlink/to/create - - - - symlink/target/path
52 c /dev/char-device-to-create mode user group - -
53 b /dev/block-device-to-create mode user group - -
54 # p+, L+, c+, b+ create target unconditionally, w+ appends to the file
55 C /target/to/create - - - - /source/to/copy
56 x /path-or-glob/to/ignore - - - - -
57 X /path-or-glob/to/ignore/recursively - - - - -
58 r /empty/dir/to/remove - - - - -
59 R /dir/to/remove/recursively - - - - -
60 z /path-or-glob/to/adjust/mode mode user group - MAC context
61 Z /path-or-glob/to/adjust/mode/recursively mode user group - MAC context
62 t /path-or-glob/to/set/xattrs - - - - xattrs
63 T /path-or-glob/to/set/xattrs/recursively - - - - xattrs
64 h /path-or-glob/to/set/attrs - - - - file attrs
65 H /path-or-glob/to/set/attrs/recursively - - - - file attrs
66 a /path-or-glob/to/set/acls - - - - POSIX ACLs
67 A /path-or-glob/to/set/acls/recursively - - - - POSIX ACLs
73 <title>Description
</title>
75 <para><filename>tmpfiles.d
</filename> configuration files provide a generic mechanism to define the
76 <emphasis>creation
</emphasis> of regular files, directories, pipes, and device nodes, adjustments to
77 their
<emphasis>access mode, ownership, attributes, quota assignments, and contents
</emphasis>, and
78 finally their time-based
<emphasis>removal
</emphasis>. It is mostly commonly used for volatile and
79 temporary files and directories (such as those located under
<filename>/run
</filename>,
80 <filename>/tmp
</filename>,
<filename>/var/tmp
</filename>, the API file systems such as
81 <filename>/sys
</filename> or
<filename>/proc
</filename>, as well as some other directories below
82 <filename>/var
</filename>).
</para>
84 <para><command>systemd-tmpfiles
</command> uses this configuration to create volatile files and
85 directories during boot and to do periodic cleanup afterwards. See
86 <citerefentry><refentrytitle>systemd-tmpfiles
</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
87 the description of
<filename>systemd-tmpfiles-setup.service
</filename>,
88 <filename>systemd-tmpfiles-cleanup.service
</filename>, and associated units.
</para>
90 <para>System daemons frequently require private runtime directories below
<filename>/run
</filename> to
91 store communication sockets and similar. For these, is is better to use
92 <varname>RuntimeDirectory=
</varname> in their unit files (see
93 <citerefentry><refentrytitle>systemd.exec
</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
94 details), if the flexibility provided by
<filename>tmpfiles.d
</filename> is not required. The advantages
95 are that the configuration required by the unit is centralized in one place, and that the lifetime of the
96 directory is tied to the lifetime of the service itself. Similarly,
<varname>StateDirectory=
</varname>,
97 <varname>CacheDirectory=
</varname>,
<varname>LogsDirectory=
</varname>, and
98 <varname>ConfigurationDirectory=
</varname> should be used to create directories under
99 <filename>/var/lib/
</filename>,
<filename>/var/cache/
</filename>,
<filename>/var/log/
</filename>, and
100 <filename>/etc/
</filename>.
<filename>tmpfiles.d
</filename> should be used for files whose lifetime is
101 independent of any service or requires more complicated configuration.
</para>
105 <title>Configuration Directories and Precedence
</title>
107 <para>Each configuration file shall be named in the style of
108 <filename><replaceable>package
</replaceable>.conf
</filename> or
109 <filename><replaceable>package
</replaceable>-
<replaceable>part
</replaceable>.conf
</filename>.
110 The second variant should be used when it is desirable to make it
111 easy to override just this part of configuration.
</para>
113 <para>Files in
<filename>/etc/tmpfiles.d
</filename> override files with the same name in
114 <filename>/usr/lib/tmpfiles.d
</filename> and
<filename>/run/tmpfiles.d
</filename>. Files in
115 <filename>/run/tmpfiles.d
</filename> override files with the same name in
116 <filename>/usr/lib/tmpfiles.d
</filename>. Packages should install their configuration files in
117 <filename>/usr/lib/tmpfiles.d
</filename>. Files in
<filename>/etc/tmpfiles.d
</filename> are reserved for the local
118 administrator, who may use this logic to override the configuration files installed by vendor packages. All
119 configuration files are sorted by their filename in lexicographic order, regardless of which of the directories
120 they reside in. If multiple files specify the same path, the entry in the file with the lexicographically earliest
121 name will be applied. All other conflicting entries will be logged as errors. When two lines are prefix path and
122 suffix path of each other, then the prefix line is always created first, the suffix later (and if removal applies
123 to the line, the order is reversed: the suffix is removed first, the prefix later). Lines that take globs are
124 applied after those accepting no globs. If multiple operations shall be applied on the same file (such as ACL,
125 xattr, file attribute adjustments), these are always done in the same fixed order. Except for those cases, the
126 files/directories are processed in the order they are listed.
</para>
128 <para>If the administrator wants to disable a configuration file
129 supplied by the vendor, the recommended way is to place a symlink
130 to
<filename>/dev/null
</filename> in
131 <filename>/etc/tmpfiles.d/
</filename> bearing the same filename.
136 <title>Configuration File Format
</title>
138 <para>The configuration format is one line per path containing
139 type, path, mode, ownership, age, and argument fields:
</para>
141 <programlisting>#Type Path Mode User Group Age Argument
142 d /run/user
0755 root root
10d -
143 L /tmp/foobar - - - - /dev/null
</programlisting>
145 <para>Fields may be enclosed within quotes and contain C-style escapes.
</para>
150 <para>The type consists of a single letter and optionally an
151 exclamation mark and/or minus sign.
</para>
153 <para>The following line types are understood:
</para>
157 <term><varname>f
</varname></term>
158 <term><varname>f+
</varname></term>
159 <listitem><para><varname>f
</varname> will create a file if it does not exist yet. If the argument
160 parameter is given and the file did not exist yet, it will be written to the file.
161 <varname>f+
</varname> will create or truncate the file. If the argument parameter is given, it will
162 be written to the file. Does not follow symlinks.
</para></listitem>
166 <term><varname>w
</varname></term>
167 <term><varname>w+
</varname></term>
168 <listitem><para>Write the argument parameter to a file, if the file exists.
169 If suffixed with
<varname>+
</varname>, the line will be appended to the file.
170 If your configuration writes multiple lines to the same file, use
<varname>w+
</varname>.
171 Lines of this type accept shell-style globs in place of normal path names.
172 The argument parameter will be written without a trailing newline.
173 C-style backslash escapes are interpreted. Follows symlinks.
</para></listitem>
177 <term><varname>d
</varname></term>
178 <listitem><para>Create a directory. The mode and ownership will be adjusted if specified. Contents
179 of this directory are subject to time based cleanup if the age argument is specified.
184 <term><varname>D
</varname></term>
185 <listitem><para>Similar to
<varname>d
</varname>, but in addition the contents of the directory will
186 be removed when
<option>--remove
</option> is used.
</para></listitem>
190 <term><varname>e
</varname></term>
191 <listitem><para>Adjust the mode and ownership of existing directories and remove their contents
193 Lines of this type accept shell-style globs in place of normal path names. Contents of the
194 directories are subject to time based cleanup if the age argument is specified. If the age argument
195 is
<literal>0</literal>, contents will be unconditionally deleted every time
196 <command>systemd-tmpfiles --clean
</command> is run.
</para>
198 <para>For this entry to be useful, at least one of the mode, user, group, or age arguments must be
199 specified, since otherwise this entry has no effect. As an exception, an entry with no effect may
200 be useful when combined with
<varname>!
</varname>, see the examples.
</para></listitem>
204 <term><varname>v
</varname></term>
205 <listitem><para>Create a subvolume if the path does not exist yet, the file system supports
206 subvolumes (btrfs), and the system itself is installed into a subvolume (specifically: the root
207 directory
<filename>/
</filename> is itself a subvolume). Otherwise, create a normal directory, in
208 the same way as
<varname>d
</varname>.
</para>
210 <para>A subvolume created with this line type is not assigned to any higher-level quota group. For
211 that, use
<varname>q
</varname> or
<varname>Q
</varname>, which allow creating simple quota group
212 hierarchies, see below.
</para></listitem>
216 <term><varname>q
</varname></term>
217 <listitem><para>Create a subvolume or directory the same as
<varname>v
</varname>, but assign the
218 subvolume to the same higher-level quota groups as the parent. This ensures that higher-level
219 limits and accounting applied to the parent subvolume also include the specified subvolume. On
220 non-btrfs file systems, this line type is identical to
<varname>d
</varname>.
</para>
222 <para>If the subvolume already exists, no change to the quota hierarchy is made, regardless of whether the
223 subvolume is already attached to a quota group or not. Also see
<varname>Q
</varname> below. See
<citerefentry
224 project='die-net'
><refentrytitle>btrfs-qgroup
</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
225 details about the btrfs quota group concept.
</para></listitem>
229 <term><varname>Q
</varname></term>
230 <listitem><para>Create the subvolume or directory the same as
<varname>v
</varname>, but assign the
231 new subvolume to a new leaf quota group. Instead of copying the higher-level quota group
232 assignments from the parent as is done with
<varname>q
</varname>, the lowest quota group of the
233 parent subvolume is determined that is not the leaf quota group. Then, an
"intermediary" quota
234 group is inserted that is one level below this level, and shares the same ID part as the specified
235 subvolume. If no higher-level quota group exists for the parent subvolume, a new quota group at
236 level
255 sharing the same ID as the specified subvolume is inserted instead. This new intermediary
237 quota group is then assigned to the parent subvolume's higher-level quota groups, and the specified
238 subvolume's leaf quota group is assigned to it.
</para>
240 <para>Effectively, this has a similar effect as
<varname>q
</varname>, however introduces a new higher-level
241 quota group for the specified subvolume that may be used to enforce limits and accounting to the specified
242 subvolume and children subvolume created within it. Thus, by creating subvolumes only via
243 <varname>q
</varname> and
<varname>Q
</varname>, a concept of
"subtree quotas" is implemented. Each subvolume
244 for which
<varname>Q
</varname> is set will get a
"subtree" quota group created, and all child subvolumes
245 created within it will be assigned to it. Each subvolume for which
<varname>q
</varname> is set will not get
246 such a
"subtree" quota group, but it is ensured that they are added to the same
"subtree" quota group as
247 their immediate parents.
</para>
249 <para>It is recommended to use
<varname>Q
</varname> for subvolumes that typically contain further subvolumes,
250 and where it is desirable to have accounting and quota limits on all child subvolumes together. Examples for
251 <varname>Q
</varname> are typically
<filename>/home
</filename> or
<filename>/var/lib/machines
</filename>. In
252 contrast,
<varname>q
</varname> should be used for subvolumes that either usually do not include further
253 subvolumes or where no accounting and quota limits are needed that apply to all child subvolumes
254 together. Examples for
<varname>q
</varname> are typically
<filename>/var
</filename> or
255 <filename>/var/tmp
</filename>.
</para>
257 <para>As with
<varname>q
</varname>,
<varname>Q
</varname> has no effect on the quota group hierarchy if the
258 subvolume already exists, regardless of whether the subvolume already belong to a quota group or not.
263 <term><varname>p
</varname></term>
264 <term><varname>p+
</varname></term>
265 <listitem><para>Create a named pipe (FIFO) if it does not
266 exist yet. If suffixed with
<varname>+
</varname> and a file
267 already exists where the pipe is to be created, it will be
268 removed and be replaced by the pipe.
</para></listitem>
272 <term><varname>L
</varname></term>
273 <term><varname>L+
</varname></term>
274 <listitem><para>Create a symlink if it does not exist
275 yet. If suffixed with
<varname>+
</varname> and a file or
276 directory already exists where the symlink is to be created,
277 it will be removed and be replaced by the symlink. If the
278 argument is omitted, symlinks to files with the same name
279 residing in the directory
280 <filename>/usr/share/factory/
</filename> are created. Note
281 that permissions and ownership on symlinks are ignored.
286 <term><varname>c
</varname></term>
287 <term><varname>c+
</varname></term>
288 <listitem><para>Create a character device node if it does
289 not exist yet. If suffixed with
<varname>+
</varname> and a
290 file already exists where the device node is to be created,
291 it will be removed and be replaced by the device node. It is
292 recommended to suffix this entry with an exclamation mark to
293 only create static device nodes at boot, as udev will not
294 manage static device nodes that are created at runtime.
299 <term><varname>b
</varname></term>
300 <term><varname>b+
</varname></term>
301 <listitem><para>Create a block device node if it does not
302 exist yet. If suffixed with
<varname>+
</varname> and a file
303 already exists where the device node is to be created, it
304 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.
312 <term><varname>C
</varname></term>
313 <listitem><para>Recursively copy a file or directory, if the
314 destination files or directories do not exist yet or the
315 destination directory is empty. Note that this command will not
316 descend into subdirectories if the destination directory already
317 exists and is not empty. Instead, the entire copy operation is
318 skipped. If the argument is omitted, files from the source directory
319 <filename>/usr/share/factory/
</filename> with the same name
320 are copied. Does not follow symlinks.
</para></listitem>
324 <term><varname>x
</varname></term>
325 <listitem><para>Ignore a path during cleaning. Use this type
326 to exclude paths from clean-up as controlled with the Age
327 parameter. Note that lines of this type do not influence the
328 effect of
<varname>r
</varname> or
<varname>R
</varname>
329 lines. Lines of this type accept shell-style globs in place
330 of normal path names.
</para></listitem>
334 <term><varname>X
</varname></term>
335 <listitem><para>Ignore a path during cleaning. Use this type
336 to exclude paths from clean-up as controlled with the Age
337 parameter. Unlike
<varname>x
</varname>, this parameter will
338 not exclude the content if path is a directory, but only
339 directory itself. Note that lines of this type do not
340 influence the effect of
<varname>r
</varname> or
341 <varname>R
</varname> lines. Lines of this type accept
342 shell-style globs in place of normal path names.
347 <term><varname>r
</varname></term>
348 <listitem><para>Remove a file or directory if it exists.
349 This may not be used to remove non-empty directories, use
350 <varname>R
</varname> for that. Lines of this type accept
351 shell-style globs in place of normal path
352 names. Does not follow symlinks.
</para></listitem>
356 <term><varname>R
</varname></term>
357 <listitem><para>Recursively remove a path and all its
358 subdirectories (if it is a directory). Lines of this type
359 accept shell-style globs in place of normal path
360 names. Does not follow symlinks.
</para></listitem>
364 <term><varname>z
</varname></term>
365 <listitem><para>Adjust the access mode, user and group ownership, and restore the SELinux security
366 context of a file or directory, if it exists. Lines of this type accept shell-style globs in place
367 of normal path names. Does not follow symlinks.
</para></listitem>
371 <term><varname>Z
</varname></term>
372 <listitem><para>Recursively set the access mode, user and group ownership, and restore the SELinux
373 security context of a file or directory if it exists, as well as of its subdirectories and the
374 files contained therein (if applicable). Lines of this type accept shell-style globs in place of
375 normal path names. Does not follow symlinks.
</para></listitem>
379 <term><varname>t
</varname></term>
380 <listitem><para>Set extended attributes, see
<citerefentry
381 project='man-pages'
><refentrytitle>attr
</refentrytitle>
382 <manvolnum>5</manvolnum></citerefentry> for details. The argument field should take one or more
383 assignment expressions in the form
384 <replaceable>namespace
</replaceable>.
<replaceable>attribute
</replaceable>=
<replaceable>value
</replaceable>,
385 for examples see below. Lines of this type accept shell-style globs in place of normal path
386 names. This can be useful for setting SMACK labels. Does not follow symlinks.
</para>
388 <para>Please note that extended attributes settable with this line type are a different concept
389 from the Linux file attributes settable with
<varname>h
</varname>/
<varname>H
</varname>, see
390 below.
</para></listitem>
394 <term><varname>T
</varname></term>
395 <listitem><para>Same as
<varname>t
</varname>, but operates recursively.
</para></listitem>
399 <term><varname>h
</varname></term>
400 <listitem><para>Set Linux file/directory attributes. Lines of this type accept shell-style globs in
401 place of normal path names.
</para>
403 <para>The format of the argument field is
<varname>[+-=][aAcCdDeijPsStTu]
</varname>. The prefix
404 <varname>+
</varname> (the default one) causes the attribute(s) to be added;
<varname>-
</varname>
405 causes the attribute(s) to be removed;
<varname>=
</varname> causes the attributes to be set exactly
406 as the following letters. The letters
<literal>aAcCdDeijPsStTu
</literal> select the new attributes
407 for the files, see
<citerefentry project='man-pages'
><refentrytitle>chattr
</refentrytitle>
408 <manvolnum>1</manvolnum></citerefentry> for further information.
411 <para>Passing only
<varname>=
</varname> as argument resets all the file attributes listed above. It
412 has to be pointed out that the
<varname>=
</varname> prefix limits itself to the attributes
413 corresponding to the letters listed here. All other attributes will be left untouched. Does not
414 follow symlinks.
</para>
416 <para>Please note that the Linux file attributes settable with this line type are a different
417 concept from the extended attributes settable with
<varname>t
</varname>/
<varname>T
</varname>,
418 see above.
</para></listitem>
422 <term><varname>H
</varname></term>
423 <listitem><para>Sames as
<varname>h
</varname>, but operates recursively.
</para></listitem>
427 <term><varname>a
</varname></term>
428 <term><varname>a+
</varname></term>
429 <listitem><para>Set POSIX ACLs (access control lists), see
<citerefentry
430 project='man-pages'
><refentrytitle>acl
</refentrytitle>
431 <manvolnum>5</manvolnum></citerefentry>. If suffixed with
<varname>+
</varname>, the specified
432 entries will be added to the existing set.
<command>systemd-tmpfiles
</command> will automatically
433 add the required base entries for user and group based on the access mode of the file, unless base
434 entries already exist or are explicitly specified. The mask will be added if not specified
435 explicitly or already present. Lines of this type accept shell-style globs in place of normal path
436 names. This can be useful for allowing additional access to certain files. Does not follow
437 symlinks.
</para></listitem>
441 <term><varname>A
</varname></term>
442 <term><varname>A+
</varname></term>
443 <listitem><para>Same as
<varname>a
</varname> and
444 <varname>a+
</varname>, but recursive. Does not follow
445 symlinks.
</para></listitem>
449 <para>If the exclamation mark is used, this line is only safe to
450 execute during boot, and can break a running system. Lines
451 without the exclamation mark are presumed to be safe to execute
452 at any time, e.g. on package upgrades.
453 <command>systemd-tmpfiles
</command> will execute line with an
454 exclamation mark only if option
<option>--boot
</option> is
458 <programlisting># Make sure these are created by default so that nobody else can
459 d /tmp/.X11-unix
1777 root root
10d
461 # Unlink the X11 lock files
462 r! /tmp/.X[
0-
9]*-lock
</programlisting>
463 The second line in contrast to the first one would break a
464 running system, and will only be executed with
465 <option>--boot
</option>.
</para>
467 <para>If the minus sign is used, this line failing to run
468 successfully during create (and only create) will not cause
469 the execution of
<command>systemd-tmpfiles
</command> to return
473 <programlisting># Modify sysfs but don't fail if we are in a container with a read-only /proc
474 w- /proc/sys/vm/swappiness - - - -
10</programlisting></para>
476 <para>Note that for all line types that result in creation of any kind of file node
477 (i.e.
<varname>f
</varname>/
<varname>F
</varname>,
478 <varname>d
</varname>/
<varname>D
</varname>/
<varname>v
</varname>/
<varname>q
</varname>/
<varname>Q
</varname>,
479 <varname>p
</varname>,
<varname>L
</varname>,
<varname>c
</varname>/
<varname>b
</varname> and
<varname>C
</varname>)
480 leading directories are implicitly created if needed, owned by root with an access mode of
0755. In order to
481 create them with different modes or ownership make sure to add appropriate
<varname>d
</varname> lines.
</para>
487 <para>The file system path specification supports simple
488 specifier expansion, see below. The path (after expansion) must be
495 <para>The file access mode to use when creating this file or
496 directory. If omitted or when set to
<literal>-
</literal>, the
497 default is used:
0755 for directories,
0644 for all other file
498 objects. For
<varname>z
</varname>,
<varname>Z
</varname> lines,
499 if omitted or when set to
<literal>-
</literal>, the file access
500 mode will not be modified. This parameter is ignored for
501 <varname>x
</varname>,
<varname>r
</varname>,
502 <varname>R
</varname>,
<varname>L
</varname>,
<varname>t
</varname>,
503 and
<varname>a
</varname> lines.
</para>
505 <para>Optionally, if prefixed with
<literal>~
</literal>, the
506 access mode is masked based on the already set access bits for
507 existing file or directories: if the existing file has all
508 executable bits unset, all executable bits are removed from the
509 new access mode, too. Similarly, if all read bits are removed
510 from the old access mode, they will be removed from the new
511 access mode too, and if all write bits are removed, they will be
512 removed from the new access mode too. In addition, the
513 sticky/SUID/SGID bit is removed unless applied to a
514 directory. This functionality is particularly useful in
515 conjunction with
<varname>Z
</varname>.
</para>
519 <title>User, Group
</title>
521 <para>The user and group to use for this file or directory. This may either be a numeric ID or a
522 user/group name. If omitted or when set to
<literal>-
</literal>, the user and group of the user who
523 invokes
<command>systemd-tmpfiles
</command> is used. For
<varname>z
</varname> and
<varname>Z
</varname>
524 lines, when omitted or when set to
<literal>-
</literal>, the file ownership will not be modified. These
525 parameters are ignored for
<varname>x
</varname>,
<varname>r
</varname>,
<varname>R
</varname>,
526 <varname>L
</varname>,
<varname>t
</varname>, and
<varname>a
</varname> lines.
</para>
528 <para>This field should generally only reference system users/groups, i.e. users/groups that are
529 guaranteed to be resolvable during early boot. If this field references users/groups that only become
530 resolveable during later boot (i.e. after NIS, LDAP or a similar networked directory service become
531 available), execution of the operations declared by the line will likely fail. Also see
<ulink
532 url=
"https://systemd.io/UIDS-GIDS.html#notes-on-resolvability-of-user-and-group-names">Notes on
533 Resolvability of User and Group Names
</ulink> for more information on requirements on system user/group
539 <para>The date field, when set, is used to decide what files to
540 delete when cleaning. If a file or directory is older than the
541 current time minus the age field, it is deleted. The field
542 format is a series of integers each followed by one of the
543 following suffixes for the respective time units:
544 <constant>s
</constant>,
545 <constant>m
</constant> or
<constant>min
</constant>,
546 <constant>h
</constant>,
547 <constant>d
</constant>,
548 <constant>w
</constant>,
549 <constant>ms
</constant>, and
550 <constant>us
</constant>,
551 meaning seconds, minutes, hours, days, weeks,
552 milliseconds, and microseconds, respectively. Full names of the time units can
556 <para>If multiple integers and units are specified, the time
557 values are summed. If an integer is given without a unit,
558 <constant>s
</constant> is assumed.
561 <para>When the age is set to zero, the files are cleaned
562 unconditionally.
</para>
564 <para>The age field only applies to lines starting with
565 <varname>d
</varname>,
<varname>D
</varname>,
<varname>e
</varname>,
566 <varname>v
</varname>,
<varname>q
</varname>,
567 <varname>Q
</varname>,
<varname>C
</varname>,
<varname>x
</varname>
568 and
<varname>X
</varname>. If omitted or set to
569 <literal>-
</literal>, no automatic clean-up is done.
</para>
571 <para>If the age field starts with a tilde character
572 <literal>~
</literal>, the clean-up is only applied to files and
573 directories one level inside the directory specified, but not
574 the files and directories immediately inside it.
</para>
576 <para>The age of a file system entry is determined from its last
577 modification timestamp (mtime), its last access timestamp (atime),
578 and (except for directories) its last status change timestamp
579 (ctime). Any of these three (or two) values will prevent cleanup
580 if it is more recent than the current time minus the age
583 <para>Note that while the aging algorithm is run a 'shared' BSD file lock (see
<citerefentry
584 project='man-pages'
><refentrytitle>flock
</refentrytitle><manvolnum>2</manvolnum></citerefentry>) is
585 taken on each directory the algorithm descends into (and each directory below that, and so on). If the
586 aging algorithm finds a lock is already taken on some directory, it (and everything below it) is
587 skipped. Applications may use this to temporarily exclude certain directory subtrees from the aging
588 algorithm: the applications can take a BSD file lock themselves, and as long as they keep it aging of
589 the directory and everything below it is disabled.
</para>
593 <title>Argument
</title>
595 <para>For
<varname>L
</varname> lines determines the destination path of the symlink. For
<varname>c
</varname> and
596 <varname>b
</varname>, determines the major/minor of the device node, with major and minor formatted as integers,
597 separated by
<literal>:
</literal>, e.g.
<literal>1:
3</literal>. For
<varname>f
</varname>,
<varname>F
</varname>,
598 and
<varname>w
</varname>, the argument may be used to specify a short string that is written to the file,
599 suffixed by a newline. For
<varname>C
</varname>, specifies the source file or directory. For
<varname>t
</varname>
600 and
<varname>T
</varname>, determines extended attributes to be set. For
<varname>a
</varname> and
601 <varname>A
</varname>, determines ACL attributes to be set. For
<varname>h
</varname> and
<varname>H
</varname>,
602 determines the file attributes to set. Ignored for all other lines.
</para>
604 <para>This field can contain specifiers, see below.
</para>
609 <title>Specifiers
</title>
611 <para>Specifiers can be used in the
"path" and
"argument" fields.
612 An unknown or unresolvable specifier is treated as invalid configuration.
613 The following expansions are understood:
</para>
615 <title>Specifiers available
</title>
616 <tgroup cols='
3' align='left' colsep='
1' rowsep='
1'
>
617 <colspec colname=
"spec" />
618 <colspec colname=
"mean" />
619 <colspec colname=
"detail" />
622 <entry>Specifier
</entry>
623 <entry>Meaning
</entry>
624 <entry>Details
</entry>
629 <entry><literal>%b
</literal></entry>
630 <entry>Boot ID
</entry>
631 <entry>The boot ID of the running system, formatted as string. See
<citerefentry><refentrytitle>random
</refentrytitle><manvolnum>4</manvolnum></citerefentry> for more information.
</entry>
634 <entry><literal>%C
</literal></entry>
635 <entry>System or user cache directory
</entry>
636 <entry>In
<option>--user
</option> mode, this is the same as
<varname>$XDG_CACHE_HOME
</varname>, and
<filename>/var/cache
</filename> otherwise.
</entry>
639 <entry><literal>%h
</literal></entry>
640 <entry>User home directory
</entry>
641 <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>
644 <entry><literal>%H
</literal></entry>
645 <entry>Host name
</entry>
646 <entry>The hostname of the running system.
</entry>
649 <entry><literal>%L
</literal></entry>
650 <entry>System or user log directory
</entry>
651 <entry>In
<option>--user
</option> mode, this is the same as
<varname>$XDG_CONFIG_HOME
</varname> with
<filename noindex='true'
>/log
</filename> appended, and
<filename>/var/log
</filename> otherwise.
</entry>
654 <entry><literal>%m
</literal></entry>
655 <entry>Machine ID
</entry>
656 <entry>The machine ID of the running system, formatted as string. See
<citerefentry><refentrytitle>machine-id
</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.
</entry>
659 <entry><literal>%S
</literal></entry>
660 <entry>System or user state directory
</entry>
661 <entry>In
<option>--user
</option> mode, this is the same as
<varname>$XDG_CONFIG_HOME
</varname>, and
<filename>/var/lib
</filename> otherwise.
</entry>
664 <entry><literal>%t
</literal></entry>
665 <entry>System or user runtime directory
</entry>
666 <entry>In
<option>--user
</option> mode, this is the same
<varname>$XDG_RUNTIME_DIR
</varname>, and
<filename>/run
</filename> otherwise.
</entry>
669 <entry><literal>%T
</literal></entry>
670 <entry>Directory for temporary files
</entry>
671 <entry>This is either
<filename>/tmp
</filename> or the path
<literal>$TMPDIR
</literal>,
<literal>$TEMP
</literal> or
<literal>$TMP
</literal> are set to.
</entry>
674 <entry><literal>%g
</literal></entry>
675 <entry>User group
</entry>
676 <entry>This is the name of the group running the command. In case of the system instance this resolves to
<literal>root
</literal>.
</entry>
679 <entry><literal>%G
</literal></entry>
680 <entry>User GID
</entry>
681 <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>
684 <entry><literal>%u
</literal></entry>
685 <entry>User name
</entry>
686 <entry>This is the name of the user running the command. In case of the system instance this resolves to
<literal>root
</literal>.
</entry>
689 <entry><literal>%U
</literal></entry>
690 <entry>User UID
</entry>
691 <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>
694 <entry><literal>%v
</literal></entry>
695 <entry>Kernel release
</entry>
696 <entry>Identical to
<command>uname -r
</command> output.
</entry>
699 <entry><literal>%V
</literal></entry>
700 <entry>Directory for larger and persistent temporary files
</entry>
701 <entry>This is either
<filename>/var/tmp
</filename> or the path
<literal>$TMPDIR
</literal>,
<literal>$TEMP
</literal> or
<literal>$TMP
</literal> are set to.
</entry>
704 <entry><literal>%%
</literal></entry>
705 <entry>Escaped
<literal>%
</literal></entry>
706 <entry>Single percent sign.
</entry>
714 <title>Examples
</title>
716 <title>Create directories with specific mode and ownership
</title>
718 <citerefentry project='die-net'
><refentrytitle>screen
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
719 needs two directories created at boot with specific modes and ownership:
</para>
721 <programlisting># /usr/lib/tmpfiles.d/screen.conf
722 d /run/screens
1777 root screen
10d
723 d /run/uscreens
0755 root screen
10d12h
726 <para>Contents of
<filename>/run/screens
</filename> and /run/uscreens will
727 be cleaned up after
10 and
10½ days, respectively.
</para>
731 <title>Create a directory with a SMACK attribute
</title>
732 <programlisting>D /run/cups - - - -
733 t /run/cups - - - - security.SMACK64=printing user.
attr-with-spaces=
"foo bar"
736 <para>The directory will be owned by root and have default mode. Its contents are
737 not subject to time based cleanup, but will be obliterated when
738 <command>systemd-tmpfiles --remove
</command> runs.
</para>
742 <title>Create a directory and prevent its contents from cleanup
</title>
744 <citerefentry project='die-net'
><refentrytitle>abrt
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
745 needs a directory created at boot with specific mode and ownership and its content
746 should be preserved from the automatic cleanup applied to the contents of
747 <filename>/var/tmp
</filename>:
</para>
749 <programlisting># /usr/lib/tmpfiles.d/tmp.conf
750 d /var/tmp
1777 root root
30d
753 <programlisting># /usr/lib/tmpfiles.d/abrt.conf
754 d /var/tmp/abrt
0755 abrt abrt -
759 <title>Apply clean up during boot and based on time
</title>
761 <programlisting># /usr/lib/tmpfiles.d/dnf.conf
762 r! /var/cache/dnf/*/*/download_lock.pid
763 r! /var/cache/dnf/*/*/metadata_lock.pid
764 r! /var/lib/dnf/rpmdb_lock.pid
765 e /var/cache/dnf/ - - -
30d
768 <para>The lock files will be removed during boot. Any files and directories in
769 <filename>/var/cache/dnf/
</filename> will be removed after they have not been
770 accessed in
30 days.
</para>
774 <title>Empty the contents of a cache directory on boot
</title>
776 <programlisting># /usr/lib/tmpfiles.d/krb5rcache.conf
777 e! /var/cache/krb5rcache - - -
0
780 <para>Any files and subdirectories in
<filename>/var/cache/krb5rcache/
</filename>
781 will be removed on boot. The directory will not be created.
787 <title><filename>/run/
</filename> and
<filename>/var/run/
</filename></title>
788 <para><filename>/var/run/
</filename> is a deprecated symlink to
<filename>/run/
</filename>, and
789 applications should use the latter.
<command>systemd-tmpfiles
</command> will warn if
790 <filename>/var/run/
</filename> is used.
</para>
794 <title>See Also
</title>
796 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
797 <citerefentry><refentrytitle>systemd-tmpfiles
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
798 <citerefentry><refentrytitle>systemd-delta
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
799 <citerefentry><refentrytitle>systemd.exec
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
800 <citerefentry project='man-pages'
><refentrytitle>attr
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
801 <citerefentry project='man-pages'
><refentrytitle>getfattr
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
802 <citerefentry project='man-pages'
><refentrytitle>setfattr
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
803 <citerefentry project='man-pages'
><refentrytitle>setfacl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
804 <citerefentry project='man-pages'
><refentrytitle>getfacl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
805 <citerefentry project='man-pages'
><refentrytitle>chattr
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
806 <citerefentry project='die-net'
><refentrytitle>btrfs-subvolume
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
807 <citerefentry project='die-net'
><refentrytitle>btrfs-qgroup
</refentrytitle><manvolnum>8</manvolnum></citerefentry>