man/tmpfiles.d.xml

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