man/tmpfiles.d.xml

   1 <?xml version="1.0"?>
   2 <!--*-nxml-*-->
   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!--
   5   This file is part of systemd.
   6
   7   Copyright 2010 Brandon Philips
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 -->
  22 <refentry id="tmpfiles.d">
  23
  24         <refentryinfo>
  25                 <title>tmpfiles.d</title>
  26                 <productname>systemd</productname>
  27
  28                 <authorgroup>
  29                         <author>
  30                                 <contrib>Documentation</contrib>
  31                                 <firstname>Brandon</firstname>
  32                                 <surname>Philips</surname>
  33                                 <email>brandon@ifup.org</email>
  34                         </author>
  35                 </authorgroup>
  36         </refentryinfo>
  37
  38         <refmeta>
  39                 <refentrytitle>tmpfiles.d</refentrytitle>
  40                 <manvolnum>5</manvolnum>
  41         </refmeta>
  42
  43         <refnamediv>
  44                 <refname>tmpfiles.d</refname>
  45                 <refpurpose>Configuration for creation, deletion and
  46                 cleaning of volatile and temporary files</refpurpose>
  47         </refnamediv>
  48
  49         <refsynopsisdiv>
  50                 <para><filename>/etc/tmpfiles.d/*.conf</filename></para>
  51                 <para><filename>/run/tmpfiles.d/*.conf</filename></para>
  52                 <para><filename>/usr/lib/tmpfiles.d/*.conf</filename></para>
  53         </refsynopsisdiv>
  54
  55         <refsect1>
  56                 <title>Description</title>
  57
  58                 <para><command>systemd-tmpfiles</command> uses the
  59                 configuration files from the above directories to describe the
  60                 creation, cleaning and removal of volatile and
  61                 temporary files and directories which usually reside
  62                 in directories such as <filename>/run</filename>
  63                 or <filename>/tmp</filename>.</para>
  64         </refsect1>
  65
  66         <refsect1>
  67                 <title>Configuration Format</title>
  68
  69                 <para>Each configuration file shall be named in the
  70                 style of <filename>&lt;package&gt;.conf</filename>.
  71                 Files in <filename>/etc/</filename> override files
  72                 with the same name in <filename>/usr/lib/</filename>
  73                 and <filename>/run/</filename>.  Files in
  74                 <filename>/run/</filename> override files with the same
  75                 name in <filename>/usr/lib/</filename>. Packages
  76                 should install their configuration files in
  77                 <filename>/usr/lib/</filename>. Files in
  78                 <filename>/etc/</filename> are reserved for the local
  79                 administrator, who may use this logic to override the
  80                 configuration files installed by vendor packages. All
  81                 configuration files are sorted by their filename in
  82                 lexicographic order, regardless in which of the
  83                 directories they reside. If multiple files specify the
  84                 same path, the entry in the file with the lexicographically
  85                 earliest name will be applied, all all other conflicting
  86                 entries logged as errors.</para>
  87
  88                 <para>If the administrator wants to disable a
  89                 configuration file supplied by the vendor, the
  90                 recommended way is to place a symlink to
  91                 <filename>/dev/null</filename> in
  92                 <filename>/etc/tmpfiles.d/</filename> bearing the
  93                 same filename.</para>
  94
  95                 <para>The configuration format is one line per path
  96                 containing action, path, mode, ownership, age and argument
  97                 fields:</para>
  98
  99                 <programlisting>Type Path        Mode UID  GID  Age Argument
 100 d    /run/user   0755 root root 10d -
 101 L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
 102
 103
 104                 <refsect2>
 105                         <title>Type</title>
 106
 107                         <para>The following line types are understood:</para>
 108
 109                         <variablelist>
 110                                 <varlistentry>
 111                                         <term><varname>f</varname></term>
 112                                         <listitem><para>Create a file if it does not exist yet (optionally writing a short string into it, if the argument parameter is passed)</para></listitem>
 113                                 </varlistentry>
 114
 115                                 <varlistentry>
 116                                         <term><varname>F</varname></term>
 117                                         <listitem><para>Create or truncate a file (optionally writing a short string into it, if the argument parameter is passed)</para></listitem>
 118                                 </varlistentry>
 119
 120                                 <varlistentry>
 121                                         <term><varname>w</varname></term>
 122                                         <listitem><para>Write the argument parameter to a file, if the file exists.
 123                                             Lines of this type accept shell-style globs in place of normal path
 124                                             names. The argument parameter will be written without a trailing
 125                                             newline. C-style backslash escapes are interpreted.</para></listitem>
 126                                 </varlistentry>
 127
 128                                 <varlistentry>
 129                                         <term><varname>d</varname></term>
 130                                         <listitem><para>Create a directory if it does not exist yet</para></listitem>
 131                                 </varlistentry>
 132
 133                                 <varlistentry>
 134                                         <term><varname>D</varname></term>
 135                                         <listitem><para>Create or empty a directory</para></listitem>
 136                                 </varlistentry>
 137
 138                                 <varlistentry>
 139                                         <term><varname>p</varname></term>
 140                                         <listitem><para>Create a named pipe (FIFO) if it does not exist yet</para></listitem>
 141                                 </varlistentry>
 142
 143                                 <varlistentry>
 144                                         <term><varname>L</varname></term>
 145                                         <listitem><para>Create a symlink if it does not exist yet</para></listitem>
 146                                 </varlistentry>
 147
 148                                 <varlistentry>
 149                                         <term><varname>c</varname></term>
 150                                         <listitem><para>Create a character device node if it does not exist yet</para></listitem>
 151                                 </varlistentry>
 152
 153                                 <varlistentry>
 154                                         <term><varname>b</varname></term>
 155                                         <listitem><para>Create a block device node if it does not exist yet</para></listitem>
 156                                 </varlistentry>
 157
 158                                 <varlistentry>
 159                                         <term><varname>m</varname></term>
 160                                         <listitem><para>If the
 161                                         specified file path exists,
 162                                         adjust its access mode, group
 163                                         and user to the specified
 164                                         values and reset the SELinux
 165                                         label. If it does not exist, do
 166                                         nothing.</para></listitem>
 167                                 </varlistentry>
 168
 169                                 <varlistentry>
 170                                         <term><varname>x</varname></term>
 171                                         <listitem><para>Ignore a path
 172                                         during cleaning. Use this type
 173                                         to exclude paths from clean-up
 174                                         as controlled with the Age
 175                                         parameter. Note that lines of
 176                                         this type do not influence the
 177                                         effect of r or R lines. Lines
 178                                         of this type accept
 179                                         shell-style globs in place of
 180                                         normal path
 181                                         names.</para></listitem>
 182                                 </varlistentry>
 183
 184                                 <varlistentry>
 185                                         <term><varname>X</varname></term>
 186                                         <listitem><para>Ignore a path
 187                                         during cleaning. Use this type
 188                                         to exclude paths from clean-up
 189                                         as controlled with the Age
 190                                         parameter. Unlike x, this
 191                                         parameter will not exclude the
 192                                         content if path is a directory,
 193                                         but only directory itself.
 194                                         Note that lines of this type do
 195                                         not influence the effect of r
 196                                         or R lines. Lines of this type
 197                                         accept shell-style globs in
 198                                         place of normal path
 199                                         names.</para></listitem>
 200                                 </varlistentry>
 201
 202                                 <varlistentry>
 203                                         <term><varname>r</varname></term>
 204                                         <listitem><para>Remove a file
 205                                         or directory if it
 206                                         exists. This may not be used
 207                                         to remove non-empty
 208                                         directories, use R for
 209                                         that. Lines of this type
 210                                         accept shell-style globs in
 211                                         place of normal path
 212                                         names.</para></listitem>
 213                                 </varlistentry>
 214
 215                                 <varlistentry>
 216                                         <term><varname>R</varname></term>
 217                                         <listitem><para>Recursively
 218                                         remove a path and all its
 219                                         subdirectories (if it is a
 220                                         directory). Lines of this type
 221                                         accept shell-style globs in
 222                                         place of normal path
 223                                         names.</para></listitem>
 224                                 </varlistentry>
 225
 226                                 <varlistentry>
 227                                         <term><varname>z</varname></term>
 228                                         <listitem><para>Restore
 229                                         SELinux security context label
 230                                         and set ownership and access
 231                                         mode of a file or directory if
 232                                         it exists.  Lines of this type
 233                                         accept shell-style globs in
 234                                         place of normal path names.
 235                                         </para></listitem>
 236                                 </varlistentry>
 237
 238                                 <varlistentry>
 239                                         <term><varname>Z</varname></term>
 240                                         <listitem><para>Recursively
 241                                         restore SELinux security
 242                                         context label and set
 243                                         ownership and access mode of a
 244                                         path and all its
 245                                         subdirectories (if it is a
 246                                         directory). Lines of this type
 247                                         accept shell-style globs in
 248                                         place of normal path
 249                                         names.</para></listitem>
 250                                 </varlistentry>
 251                         </variablelist>
 252                 </refsect2>
 253
 254                 <refsect2>
 255                         <title>Path</title>
 256
 257                         <para>The file system path specification supports simple specifier
 258                         expansion. The following expansions are
 259                         understood:</para>
 260
 261                         <table>
 262                                 <title>Specifiers available</title>
 263                                 <tgroup cols='3' align='left' colsep='1' rowsep='1'>
 264                                         <colspec colname="spec" />
 265                                         <colspec colname="mean" />
 266                                         <colspec colname="detail" />
 267                                         <thead>
 268                                                 <row>
 269                                                         <entry>Specifier</entry>
 270                                                         <entry>Meaning</entry>
 271                                                         <entry>Details</entry>
 272                                                 </row>
 273                                         </thead>
 274                                         <tbody>
 275                                                 <row>
 276                                                         <entry><literal>%m</literal></entry>
 277                                                         <entry>Machine ID</entry>
 278                                                         <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>
 279                                                 </row>
 280                                                 <row>
 281                                                         <entry><literal>%b</literal></entry>
 282                                                         <entry>Boot ID</entry>
 283                                                         <entry>The boot ID of the running system, formatted as string. See <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry> for more information.</entry>
 284                                                 </row>
 285                                                 <row>
 286                                                         <entry><literal>%H</literal></entry>
 287                                                         <entry>Host name</entry>
 288                                                         <entry>The hostname of the running system.</entry>
 289                                                 </row>
 290                                                 <row>
 291                                                         <entry><literal>%v</literal></entry>
 292                                                         <entry>Kernel release</entry>
 293                                                         <entry>Identical to <command>uname -r</command> output.</entry>
 294                                                 </row>
 295                                                 <row>
 296                                                         <entry><literal>%%</literal></entry>
 297                                                         <entry>Escaped %</entry>
 298                                                         <entry>Single percent sign.</entry>
 299                                                 </row>
 300                                         </tbody>
 301                                 </tgroup>
 302                         </table>
 303                 </refsect2>
 304
 305                 <refsect2>
 306                         <title>Mode</title>
 307
 308                         <para>The file access mode to use when
 309                         creating this file or directory. If omitted or
 310                         when set to -, the default is used: 0755 for
 311                         directories, 0644 for all other file
 312                         objects. For z, Z lines, if omitted or when set
 313                         to -, the file access mode will not be
 314                         modified. This parameter is ignored for x, r,
 315                         R, L lines.</para>
 316                 </refsect2>
 317
 318                 <refsect2>
 319                         <title>UID, GID</title>
 320
 321                         <para>The user and group to use for this file
 322                         or directory. This may either be a numeric
 323                         user/group ID or a user or group name. If
 324                         omitted or when set to -, the default 0 (root)
 325                         is used. For z, Z lines, when omitted or when set to -,
 326                         the file ownership will not be modified.
 327                         These parameters are ignored for x, r, R, L lines.</para>
 328                 </refsect2>
 329
 330                 <refsect2>
 331                         <title>Age</title>
 332                         <para>The date field, when set, is used to
 333                         decide what files to delete when cleaning. If
 334                         a file or directory is older than the current
 335                         time minus the age field, it is deleted. The
 336                         field format is a series of integers each
 337                         followed by one of the following
 338                         postfixes for the respective time units:</para>
 339
 340                         <variablelist>
 341                                 <varlistentry>
 342                                 <term><varname>s</varname></term>
 343                                 <term><varname>min</varname></term>
 344                                 <term><varname>h</varname></term>
 345                                 <term><varname>d</varname></term>
 346                                 <term><varname>w</varname></term>
 347                                 <term><varname>ms</varname></term>
 348                                 <term><varname>m</varname></term>
 349                                 <term><varname>us</varname></term></varlistentry>
 350                         </variablelist>
 351
 352                         <para>If multiple integers and units are specified, the time
 353                         values are summed up. If an integer is given without a unit,
 354                         s is assumed.
 355                         </para>
 356
 357                         <para>When the age is set to zero, the files are cleaned
 358                         unconditionally.</para>
 359
 360                         <para>The age field only applies to lines starting with
 361                         d, D and x. If omitted or set to -, no automatic clean-up
 362                         is done.</para>
 363
 364                         <para>If the age field starts with a tilde
 365                         character (~), the clean-up is only applied to
 366                         files and directories one level inside the
 367                         directory specified, but not the files and
 368                         directories immediately inside it.</para>
 369                 </refsect2>
 370
 371                 <refsect2>
 372                         <title>Argument</title>
 373
 374                         <para>For L lines determines the destination
 375                         path of the symlink. For c, b determines the
 376                         major/minor of the device node, with major and
 377                         minor formatted as integers, separated by :,
 378                         e.g. "1:3". For f, F, w may be used to specify
 379                         a short string that is written to the file,
 380                         suffixed by a newline. Ignored for all other
 381                         lines.</para>
 382                 </refsect2>
 383
 384         </refsect1>
 385
 386         <refsect1>
 387                 <title>Example</title>
 388                 <example>
 389                         <title>/etc/tmpfiles.d/screen.conf example</title>
 390                         <para><command>screen</command> needs two directories created at boot with specific modes and ownership.</para>
 391
 392                         <programlisting>d /var/run/screens  1777 root root 10d
 393 d /var/run/uscreens 0755 root root 10d12h</programlisting>
 394                 </example>
 395                 <example>
 396                         <title>/etc/tmpfiles.d/abrt.conf example</title>
 397                         <para><command>abrt</command> needs a directory created at boot with specific mode and ownership and its content should be preserved.</para>
 398
 399                         <programlisting>d /var/tmp/abrt 0755 abrt abrt
 400 x /var/tmp/abrt/*</programlisting>
 401                 </example>
 402         </refsect1>
 403
 404         <refsect1>
 405                 <title>See Also</title>
 406                 <para>
 407                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 408                         <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 409                         <citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 410                 </para>
 411         </refsect1>
 412
 413 </refentry>