man/tmpfiles.d.xml

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   7   Copyright 2010 Brandon Philips
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  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;program&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                 alphabetical order, regardless in which of the
  83                 directories they reside, to guarantee that a specific
  84                 configuration file takes precedence over another file
  85                 with an alphabetically later name.</para>
  86
  87                 <para>If the administrator wants to disable a
  88                 configuration file supplied by the vendor the
  89                 recommended way is to place a symlink to
  90                 <filename>/dev/null</filename> in
  91                 <filename>/etc/tmpfiles.d/</filename> bearing the
  92                 same filename.</para>
  93
  94                 <para>The configuration format is one line per path
  95                 containing action, path, mode, ownership, age and argument
  96                 fields:</para>
  97
  98                 <programlisting>Type Path        Mode UID  GID  Age Argument
  99 d    /run/user   0755 root root 10d -
 100 L    /tmp/foobar -    -    -    -   /dev/null</programlisting>
 101
 102                 <refsect2>
 103                         <title>Type</title>
 104                         <variablelist>
 105                                 <varlistentry>
 106                                         <term><varname>f</varname></term>
 107                                         <listitem><para>Create a file if it doesn't exist yet (optionally writing a short string into it, if the argument parameter is passed)</para></listitem>
 108                                 </varlistentry>
 109
 110                                 <varlistentry>
 111                                         <term><varname>F</varname></term>
 112                                         <listitem><para>Create or truncate a file (optionally writing a short string into it, if the argument parameter is passed)</para></listitem>
 113                                 </varlistentry>
 114
 115                                 <varlistentry>
 116                                         <term><varname>w</varname></term>
 117                                         <listitem><para>Write the argument parameter to a file, if the file exists.
 118                                             Lines of this type accept shell-style globs in place of normal path
 119                                             names. The argument parameter will be written without a trailing
 120                                             newline. C-style backslash escapes are interpreted.</para></listitem>
 121                                 </varlistentry>
 122
 123                                 <varlistentry>
 124                                         <term><varname>d</varname></term>
 125                                         <listitem><para>Create a directory if it doesn't exist yet</para></listitem>
 126                                 </varlistentry>
 127
 128                                 <varlistentry>
 129                                         <term><varname>D</varname></term>
 130                                         <listitem><para>Create or empty a directory</para></listitem>
 131                                 </varlistentry>
 132
 133                                 <varlistentry>
 134                                         <term><varname>p</varname></term>
 135                                         <listitem><para>Create a named pipe (FIFO) if it doesn't exist yet</para></listitem>
 136                                 </varlistentry>
 137
 138                                 <varlistentry>
 139                                         <term><varname>L</varname></term>
 140                                         <listitem><para>Create a symlink if it doesn't exist yet</para></listitem>
 141                                 </varlistentry>
 142
 143                                 <varlistentry>
 144                                         <term><varname>c</varname></term>
 145                                         <listitem><para>Create a character device node if it doesn't exist yet</para></listitem>
 146                                 </varlistentry>
 147
 148                                 <varlistentry>
 149                                         <term><varname>b</varname></term>
 150                                         <listitem><para>Create a block device node if it doesn't exist yet</para></listitem>
 151                                 </varlistentry>
 152
 153                                 <varlistentry>
 154                                         <term><varname>x</varname></term>
 155                                         <listitem><para>Ignore a path
 156                                         during cleaning. Use this type
 157                                         to exclude paths from clean-up
 158                                         as controlled with the Age
 159                                         parameter. Note that lines of
 160                                         this type do not influence the
 161                                         effect of r or R lines. Lines
 162                                         of this type accept
 163                                         shell-style globs in place of
 164                                         normal path
 165                                         names.</para></listitem>
 166                                 </varlistentry>
 167
 168                                 <varlistentry>
 169                                         <term><varname>X</varname></term>
 170                                         <listitem><para>Ignore a path
 171                                         during cleanup. Use this type
 172                                         to prevent path removal as
 173                                         controlled with the Age parameter.
 174                                         Note that if path is a directory,
 175                                         content of a directory is not
 176                                         excluded from clean-up, only
 177                                         directory itself. Lines of this
 178                                         type accept shell-style globs
 179                                         in place of normal path
 180                                         names.</para></listitem>
 181                                 </varlistentry>
 182
 183                                 <varlistentry>
 184                                         <term><varname>r</varname></term>
 185                                         <listitem><para>Remove a file
 186                                         or directory if it
 187                                         exists. This may not be used
 188                                         to remove non-empty
 189                                         directories, use R for
 190                                         that. Lines of this type
 191                                         accept shell-style globs in
 192                                         place of normal path
 193                                         names.</para></listitem>
 194                                 </varlistentry>
 195
 196                                 <varlistentry>
 197                                         <term><varname>R</varname></term>
 198                                         <listitem><para>Recursively
 199                                         remove a path and all its
 200                                         subdirectories (if it is a
 201                                         directory). Lines of this type
 202                                         accept shell-style globs in
 203                                         place of normal path
 204                                         names.</para></listitem>
 205                                 </varlistentry>
 206
 207                                 <varlistentry>
 208                                         <term><varname>z</varname></term>
 209                                         <listitem><para>Restore
 210                                         SELinux security context label
 211                                         and set ownership and access
 212                                         mode of a file or directory if
 213                                         it exists.  Lines of this type
 214                                         accept shell-style globs in
 215                                         place of normal path names.
 216                                         </para></listitem>
 217                                 </varlistentry>
 218
 219                                 <varlistentry>
 220                                         <term><varname>Z</varname></term>
 221                                         <listitem><para>Recursively
 222                                         restore SELinux security
 223                                         context label and set
 224                                         ownership and access mode of a
 225                                         path and all its
 226                                         subdirectories (if it is a
 227                                         directory). Lines of this type
 228                                         accept shell-style globs in
 229                                         place of normal path
 230                                         names.</para></listitem>
 231                                 </varlistentry>
 232                         </variablelist>
 233                 </refsect2>
 234
 235                 <refsect2>
 236                         <title>Mode</title>
 237
 238                         <para>The file access mode to use when
 239                         creating this file or directory. If omitted or
 240                         when set to - the default is used: 0755 for
 241                         directories, 0644 for all other file
 242                         objects. For z, Z lines if omitted or when set
 243                         to - the file access mode will not be
 244                         modified. This parameter is ignored for x, r,
 245                         R, L lines.</para>
 246                 </refsect2>
 247
 248                 <refsect2>
 249                         <title>UID, GID</title>
 250
 251                         <para>The user and group to use for this file
 252                         or directory. This may either be a numeric
 253                         user/group ID or a user or group name. If
 254                         omitted or when set to - the default 0 (root)
 255                         is used. For z, Z lines when omitted or when set to -
 256                         the file ownership will not be modified.
 257                         These parameters are ignored for x, r, R, L lines.</para>
 258                 </refsect2>
 259
 260                 <refsect2>
 261                         <title>Age</title>
 262                         <para>The date field, when set, is used to
 263                         decide what files to delete when cleaning. If
 264                         a file or directory is older than the current
 265                         time minus the age field it is deleted. The
 266                         field format is a series of integers each
 267                         followed by one of the following
 268                         postfixes for the respective time units:</para>
 269
 270                         <variablelist>
 271                                 <varlistentry>
 272                                 <term><varname>s</varname></term>
 273                                 <term><varname>min</varname></term>
 274                                 <term><varname>h</varname></term>
 275                                 <term><varname>d</varname></term>
 276                                 <term><varname>w</varname></term>
 277                                 <term><varname>ms</varname></term>
 278                                 <term><varname>m</varname></term>
 279                                 <term><varname>us</varname></term></varlistentry>
 280                         </variablelist>
 281
 282                         <para>If multiple integers and units are specified the time
 283                         values are summed up. If an integer is given without a unit,
 284                         s is assumed.
 285                         </para>
 286
 287                         <para>When the age is set to zero, the files are cleaned
 288                         unconditionally.</para>
 289
 290                         <para>The age field only applies to lines starting with
 291                         d, D and x. If omitted or set to - no automatic clean-up
 292                         is done.</para>
 293
 294                         <para>If the age field starts with a tilde
 295                         character (~) the clean-up is only applied to
 296                         files and directories one level inside the
 297                         directory specified, but not the files and
 298                         directories immediately inside it.</para>
 299                 </refsect2>
 300
 301                 <refsect2>
 302                         <title>Argument</title>
 303
 304                         <para>For L lines determines the destination
 305                         path of the symlink. For c, b determines the
 306                         major/minor of the device node, with major and
 307                         minor formatted as integers, separated by :,
 308                         e.g. "1:3". For f, F, w may be used to specify
 309                         a short string that is written to the file,
 310                         suffixed by a newline. Ignored for all other
 311                         lines.</para>
 312                 </refsect2>
 313
 314         </refsect1>
 315
 316         <refsect1>
 317                 <title>Example</title>
 318                 <example>
 319                         <title>/etc/tmpfiles.d/screen.conf example</title>
 320                         <para><command>screen</command> needs two directories created at boot with specific modes and ownership.</para>
 321
 322                         <programlisting>d /var/run/screens  1777 root root 10d
 323 d /var/run/uscreens 0755 root root 10d12h</programlisting>
 324                 </example>
 325         </refsect1>
 326
 327         <refsect1>
 328                 <title>See Also</title>
 329                 <para>
 330                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 331                         <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 332                         <citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 333                 </para>
 334         </refsect1>
 335
 336 </refentry>