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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
+ SPDX-License-Identifier: LGPL-2.1+
+
This file is part of systemd.
Copyright 2010 Brandon Philips
</refsect1>
<refsect1>
- <title>Configuration Format</title>
+ <title>Configuration Directories and Precedence</title>
<para>Each configuration file shall be named in the style of
<filename><replaceable>package</replaceable>.conf</filename> or
prefix and suffix of each other, then the prefix is always
processed first, the suffix later. Lines that take globs are
applied after those accepting no globs. If multiple operations
- shall be applied on the same file (such as ACL, xattr, file
- attribute adjustments) these are always done in the same fixed
+ shall be applied on the same file, (such as ACL, xattr, file
+ attribute adjustments), these are always done in the same fixed
order. Otherwise, the files/directories are processed in the order
they are listed.</para>
to <filename>/dev/null</filename> in
<filename>/etc/tmpfiles.d/</filename> bearing the same filename.
</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Configuration File Format</title>
<para>The configuration format is one line per path containing
type, path, mode, ownership, age, and argument fields:</para>
<programlisting>#Type Path Mode UID GID Age Argument
- d /run/user 0755 root root 10d -
- L /tmp/foobar - - - - /dev/null</programlisting>
+d /run/user 0755 root root 10d -
+L /tmp/foobar - - - - /dev/null</programlisting>
<para>Fields may be enclosed within quotes and contain C-style escapes.</para>
<varlistentry>
<term><varname>d</varname></term>
- <listitem><para>Create a directory if it does not exist yet.
- </para></listitem>
+ <listitem><para>Create a directory. The mode and ownership will be adjusted if
+ specified and the directory already exists. Contents of this directory are subject
+ to time based cleanup if the age argument is specified.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>D</varname></term>
- <listitem><para>Create or empty a directory.</para></listitem>
+ <listitem><para>Similar to <varname>d</varname>, but in addition the contents
+ of the directory will be removed when <option>--remove</option> is used.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>e</varname></term>
+ <listitem><para>Similar to <varname>d</varname>, but the directory will not be created if
+ it does not exist. Lines of this type accept shell-style globs in place of normal path
+ names. For this entry to be useful, at least one of the mode, uid, gid, or age arguments
+ must be specified, since otherwise this entry has no effect. If the age argument is
+ <literal>0</literal>, contents of the directory will be unconditionally deleted every time
+ <command>systemd-tmpfiles --clean</command> is run. This can be useful when combined with
+ <varname>!</varname>, see the examples.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>v</varname></term>
<listitem><para>Create a subvolume if the path does not
- exist yet and the file system supports this
- (btrfs). Otherwise create a normal directory, in the same
- way as <varname>d</varname>. A subvolume created with this
- line type is not assigned to any higher-level quota
- group. For that use <varname>q</varname> or
- <varname>Q</varname> which allow creating simple quota group
- hierarchies, see below.</para></listitem>
+ exist yet, the file system supports subvolumes (btrfs), and
+ the system itself is installed into a subvolume
+ (specifically: the root directory <filename>/</filename> is
+ itself a subvolume). Otherwise, create a normal directory, in
+ the same way as <varname>d</varname>. A subvolume created
+ with this line type is not assigned to any higher-level
+ quota group. For that, use <varname>q</varname> or
+ <varname>Q</varname>, which allow creating simple quota
+ group hierarchies, see below.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>q</varname></term>
- <listitem><para>Similar to <varname>v</varname>, however
+ <listitem><para>Similar to <varname>v</varname>. However,
makes sure that the subvolume will be assigned to the same
higher-level quota groups as the subvolume it has been
created in. This ensures that higher-level limits and
specified subvolume. On non-btrfs file systems, this line
type is identical to <varname>d</varname>. If the subvolume
already exists and is already assigned to one or more higher
- level quota groups no change to the quota hierarchy is
+ level quota groups, no change to the quota hierarchy is
made. Also see <varname>Q</varname> below. See <citerefentry
project='die-net'><refentrytitle>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry>
for details about the btrfs quota group
<varlistentry>
<term><varname>Q</varname></term>
- <listitem><para>Similar to <varname>q</varname>, however
+ <listitem><para>Similar to <varname>q</varname>. However,
instead of copying the higher-level quota group assignments
from the parent as-is, the lowest quota group of the parent
subvolume is determined that is not the leaf quota
enforce limits and accounting to the specified subvolume and
children subvolume created within it. Thus, by creating
subvolumes only via <varname>q</varname> and
- <varname>Q</varname> a concept of "subtree quotas" is
+ <varname>Q</varname>, a concept of "subtree quotas" is
implemented. Each subvolume for which <varname>Q</varname>
is set will get a "subtree" quota group created, and all
child subvolumes created within it will be assigned to
<term><varname>L</varname></term>
<term><varname>L+</varname></term>
<listitem><para>Create a symlink if it does not exist
- yet. If suffixed with <varname>+</varname> and a file
- already exists where the symlink is to be created, it will
- be removed and be replaced by the symlink. If the argument
- is omitted, symlinks to files with the same name residing in
- the directory <filename>/usr/share/factory/</filename> are
- created.</para></listitem>
+ yet. If suffixed with <varname>+</varname> and a file or
+ directory already exists where the symlink is to be created,
+ it will be removed and be replaced by the symlink. If the
+ argument is omitted, symlinks to files with the same name
+ residing in the directory
+ <filename>/usr/share/factory/</filename> are created. Note
+ that permissions and ownership on symlinks are ignored.
+ </para></listitem>
</varlistentry>
<varlistentry>
<varname>+</varname> (the default one) causes the
attribute(s) to be added; <varname>-</varname> causes the
attribute(s) to be removed; <varname>=</varname> causes the
- attributes to set exactly as the following letters. The
+ attributes to be set exactly as the following letters. The
letters <literal>aAcCdDeijsStTu</literal> select the new
attributes for the files, see
<citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle>
</para>
<para>Passing only <varname>=</varname> as argument resets
all the file attributes listed above. It has to be pointed
- out that the <varname>=</varname> prefix, limits itself to
+ out that the <varname>=</varname> prefix limits itself to
the attributes corresponding to the letters listed here. All
other attributes will be left untouched. Does not follow
symlinks.</para>
<term><varname>a</varname></term>
<term><varname>a+</varname></term>
<listitem><para>Set POSIX ACLs (access control lists). If
- suffixed with <varname>+</varname>, specified entries will
+ suffixed with <varname>+</varname>, the specified entries will
be added to the existing set.
<command>systemd-tmpfiles</command> will automatically add
the required base entries for user and group based on the
access mode of the file, unless base entries already exist
- or are explictly specified. The mask will be added if not
+ or are explicitly specified. The mask will be added if not
specified explicitly or already present. Lines of this type
accept shell-style globs in place of normal path names. This
can be useful for allowing additional access to certain
<para>For example:
<programlisting># Make sure these are created by default so that nobody else can
- d /tmp/.X11-unix 1777 root root 10d
+d /tmp/.X11-unix 1777 root root 10d
- # Unlink the X11 lock files
- r! /tmp/.X[0-9]*-lock</programlisting>
+# Unlink the X11 lock files
+r! /tmp/.X[0-9]*-lock</programlisting>
The second line in contrast to the first one would break a
running system, and will only be executed with
<option>--boot</option>.</para>
<para>The user and group to use for this file or directory. This
may either be a numeric user/group ID or a user or group
name. If omitted or when set to <literal>-</literal>, the
- default 0 (root) is used. For <varname>z</varname>,
+ default 0 (root) is used. For <varname>z</varname> and
<varname>Z</varname> lines, when omitted or when set to
<literal>-</literal>, the file ownership will not be
modified. These parameters are ignored for <varname>x</varname>,
delete when cleaning. If a file or directory is older than the
current time minus the age field, it is deleted. The field
format is a series of integers each followed by one of the
- following postfixes for the respective time units:
+ following suffixes for the respective time units:
<constant>s</constant>,
<constant>m</constant> or <constant>min</constant>,
<constant>h</constant>,
<constant>d</constant>,
<constant>w</constant>,
- <constant>ms</constant>,
+ <constant>ms</constant>, and
<constant>us</constant>,
- respectively meaning seconds, minutes, hours, days, weeks,
- milliseconds, and microseconds. Full names of the time units can
+ meaning seconds, minutes, hours, days, weeks,
+ milliseconds, and microseconds, respectively. Full names of the time units can
be used too.
</para>
unconditionally.</para>
<para>The age field only applies to lines starting with
- <varname>d</varname>, <varname>D</varname>,
+ <varname>d</varname>, <varname>D</varname>, <varname>e</varname>,
<varname>v</varname>, <varname>q</varname>,
<varname>Q</varname>, <varname>C</varname>, <varname>x</varname>
and <varname>X</varname>. If omitted or set to
<title>Argument</title>
<para>For <varname>L</varname> lines determines the destination
- path of the symlink. For <varname>c</varname>,
- <varname>b</varname> determines the major/minor of the device
+ path of the symlink. For <varname>c</varname> and
+ <varname>b</varname>, determines the major/minor of the device
node, with major and minor formatted as integers, separated by
<literal>:</literal>, e.g. <literal>1:3</literal>. For
<varname>f</varname>, <varname>F</varname>, and
- <varname>w</varname> may be used to specify a short string that
+ <varname>w</varname>, the argument may be used to specify a short string that
is written to the file, suffixed by a newline. For
<varname>C</varname>, specifies the source file or
- directory. For <varname>t</varname>, <varname>T</varname>
+ directory. For <varname>t</varname> and <varname>T</varname>,
determines extended attributes to be set. For
- <varname>a</varname>, <varname>A</varname> determines ACL
- attributes to be set. For <varname>h</varname>,
- <varname>H</varname> determines the file attributes to
+ <varname>a</varname> and <varname>A</varname>, determines ACL
+ attributes to be set. For <varname>h</varname> and
+ <varname>H</varname>, determines the file attributes to
set. Ignored for all other lines.</para>
</refsect2>
</refsect1>
<refsect1>
- <title>Example</title>
+ <title>Examples</title>
<example>
- <title>/etc/tmpfiles.d/screen.conf example</title>
- <para><command>screen</command> needs two directories created at
- boot with specific modes and ownership.</para>
+ <title>Create directories with specific mode and ownership</title>
+ <para>
+ <citerefentry project='die-net'><refentrytitle>screen</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ needs two directories created at boot with specific modes and ownership:</para>
+
+ <programlisting># /usr/lib/tmpfiles.d/screen.conf
+d /run/screens 1777 root screen 10d
+d /run/uscreens 0755 root screen 10d12h
+</programlisting>
+
+ <para>Contents of <filename>/run/screens</filename> and /run/uscreens will
+ cleaned up after 10 and 10½ days, respectively.</para>
+ </example>
- <programlisting>d /run/screens 1777 root root 10d
-d /run/uscreens 0755 root root 10d12h
-t /run/screen - - - - user.name="John Smith" security.SMACK64=screen</programlisting>
+ <example>
+ <title>Create a directory with a SMACK attribute</title>
+ <programlisting>D /run/cups - - - -
+t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar"
+ </programlisting>
+
+ <para>The directory will be owned by root and have default mode. Its contents are
+ not subject to time based cleanup, but will be obliterated when
+ <command>systemd-tmpfiles --remove</command> runs.</para>
+ </example>
+
+ <example>
+ <title>Create a directory and prevent its contents from cleanup</title>
+ <para>
+ <citerefentry project='die-net'><refentrytitle>abrt</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ needs a directory created at boot with specific mode and ownership and its content
+ should be preserved from the automatic cleanup applied to the contents of
+ <filename>/var/tmp</filename>:</para>
+
+ <programlisting># /usr/lib/tmpfiles.d/tmp.conf
+d /var/tmp 1777 root root 30d
+</programlisting>
+
+ <programlisting># /usr/lib/tmpfiles.d/abrt.conf
+d /var/tmp/abrt 0755 abrt abrt -
+</programlisting>
+ </example>
+
+ <example>
+ <title>Apply clean up during boot and based on time</title>
+
+ <programlisting># /usr/lib/tmpfiles.d/dnf.conf
+r! /var/cache/dnf/*/*/download_lock.pid
+r! /var/cache/dnf/*/*/metadata_lock.pid
+r! /var/lib/dnf/rpmdb_lock.pid
+e /var/cache/dnf/ - - - 30d
+</programlisting>
+
+ <para>The lock files will be removed during boot. Any files and directories in
+ <filename>/var/cache/dnf/</filename> will be removed after they have not been
+ accessed in 30 days.</para>
</example>
+
<example>
- <title>/etc/tmpfiles.d/abrt.conf example</title>
- <para><command>abrt</command> needs a directory created at boot with specific mode and ownership and its content should be preserved.</para>
+ <title>Empty the contents of a cache directory on boot</title>
- <programlisting>d /var/tmp/abrt 0755 abrt abrt
-x /var/tmp/abrt/*</programlisting>
+ <programlisting># /usr/lib/tmpfiles.d/krb5rcache.conf
+e! /var/cache/krb5rcache - - - 0
+</programlisting>
+
+ <para>Any files and subdirectories in <filename>/var/cache/krb5rcache/</filename>
+ will be removed on boot. The directory will not be created.
+ </para>
</example>
</refsect1>
projects / thirdparty / systemd.git / blobdiff