<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->

<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<refentry id="tmpfiles.d">

<refentryinfo>

<title>tmpfiles.d</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Documentation</contrib>

<firstname>Brandon</firstname>

<surname>Philips</surname>

<email>brandon@ifup.org</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>tmpfiles.d</refentrytitle>

<manvolnum>5</manvolnum>

</refmeta>

<refnamediv>

<refname>tmpfiles.d</refname>

<refpurpose>Configuration for creation, deletion and cleaning of

volatile and temporary files</refpurpose>

</refnamediv>

<refsynopsisdiv>

<para><filename>/etc/tmpfiles.d/*.conf</filename></para>

<para><filename>/run/tmpfiles.d/*.conf</filename></para>

<para><filename>/usr/lib/tmpfiles.d/*.conf</filename></para>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para><command>systemd-tmpfiles</command> uses the configuration

files from the above directories to describe the creation,

cleaning and removal of volatile and temporary files and

directories which usually reside in directories such as

<filename>/run</filename> or <filename>/tmp</filename>.</para>

<para>Volatile and temporary files and directories are those

located in <filename>/run</filename> (and its alias

<filename>/var/run</filename>), <filename>/tmp</filename>,

<filename>/var/tmp</filename>, the API file systems such as

<filename>/sys</filename> or <filename>/proc</filename>, as well

as some other directories below <filename>/var</filename>.</para>

<para>System daemons frequently require private runtime

directories below <filename>/run</filename> to place communication

sockets and similar in. For these, consider declaring them in

their unit files using <varname>RuntimeDirectory=</varname> (see

<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for details), if this is feasible.</para>

</refsect1>

<refsect1>

<title>Configuration Format</title>

<para>Each configuration file shall be named in the style of

<filename><replaceable>package</replaceable>.conf</filename> or

<filename><replaceable>package</replaceable>-<replaceable>part</replaceable>.conf</filename>.

The second variant should be used when it is desirable to make it

easy to override just this part of configuration.</para>

<para>Files in <filename>/etc/tmpfiles.d</filename> override files

with the same name in <filename>/usr/lib/tmpfiles.d</filename> and

<filename>/run/tmpfiles.d</filename>. Files in

<filename>/run/tmpfiles.d</filename> override files with the same

name in <filename>/usr/lib/tmpfiles.d</filename>. Packages should

install their configuration files in

<filename>/usr/lib/tmpfiles.d</filename>. Files in

<filename>/etc/tmpfiles.d</filename> are reserved for the local

administrator, who may use this logic to override the

configuration files installed by vendor packages. All

configuration files are sorted by their filename in lexicographic

order, regardless of which of the directories they reside in. If

multiple files specify the same path, the entry in the file with

the lexicographically earliest name will be applied. All other

conflicting entries will be logged as errors. When two lines are

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

order. Otherwise, the files/directories are processed in the order

they are listed.</para>

<para>If the administrator wants to disable a configuration file

supplied by the vendor, the recommended way is to place a symlink

to <filename>/dev/null</filename> in

<filename>/etc/tmpfiles.d/</filename> bearing the same filename.

</para>

<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>

<para>Fields may be enclosed within quotes and contain C-style escapes.</para>

<refsect2>

<title>Type</title>

<para>The type consists of a single letter and optionally an

exclamation mark.</para>

<para>The following line types are understood:</para>

<variablelist>

<varlistentry>

<term><varname>f</varname></term>

<listitem><para>Create a file if it does not exist yet. If

the argument parameter is given, it will be written to the

file. Does not follow symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>F</varname></term>

<listitem><para>Create or truncate a file. If the argument

parameter is given, it will be written to the file. Does not follow symlinks.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>w</varname></term>

<listitem><para>Write the argument parameter to a file, if

the file exists. Lines of this type accept shell-style

globs in place of normal path names. The argument parameter

will be written without a trailing newline. C-style

backslash escapes are interpreted. Follows

symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>d</varname></term>

<listitem><para>Create a directory if it does not exist yet.

</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>D</varname></term>

<listitem><para>Create or empty a directory.</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>

</varlistentry>

<varlistentry>

<term><varname>q</varname></term>

<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

accounting applied to the parent subvolume also include the

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

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

concept.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>Q</varname></term>

<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

group. Then, an "intermediary" quota group is inserted that

is one level below this level, and shares the same ID part

as the specified subvolume. If no higher-level quota group

exists for the parent subvolume, a new quota group at level

255 sharing the same ID as the specified subvolume is

inserted instead. This new intermediary quota group is then

assigned to the parent subvolume's higher-level quota

groups, and the specified subvolume's leaf quota group is

assigned to it.</para>

<para>Effectively, this has a similar effect as

<varname>q</varname>, however introduces a new higher-level

quota group for the specified subvolume that may be used to

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

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

it. Each subvolume for which <varname>q</varname> is set

will not get such a "subtree" quota group, but it is ensured

that they are added to the same "subtree" quota group as their

immediate parents.</para>

<para>It is recommended to use

<varname>Q</varname> for subvolumes that typically contain

further subvolumes, and where it is desirable to have

accounting and quota limits on all child subvolumes

together. Examples for <varname>Q</varname> are typically

<filename>/home</filename> or

<filename>/var/lib/machines</filename>. In contrast,

<varname>q</varname> should be used for subvolumes that

either usually do not include further subvolumes or where no

accounting and quota limits are needed that apply to all

child subvolumes together. Examples for <varname>q</varname>

are typically <filename>/var</filename> or

<filename>/var/tmp</filename>. As with <varname>Q</varname>,

<varname>q</varname> has no effect on the quota group

hierarchy if the subvolume exists and already has at least

one higher-level quota group assigned.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>p</varname></term>

<term><varname>p+</varname></term>

<listitem><para>Create a named pipe (FIFO) if it does not

exist yet. If suffixed with <varname>+</varname> and a file

already exists where the pipe is to be created, it will be

removed and be replaced by the pipe.</para></listitem>

</varlistentry>

<varlistentry>

<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>

</varlistentry>

<varlistentry>

<term><varname>c</varname></term>

<term><varname>c+</varname></term>

<listitem><para>Create a character device node if it does

not exist yet. If suffixed with <varname>+</varname> and a

file already exists where the device node is to be created,

it will be removed and be replaced by the device node. It is

recommended to suffix this entry with an exclamation mark to

only create static device nodes at boot, as udev will not

manage static device nodes that are created at runtime.

</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>b</varname></term>

<term><varname>b+</varname></term>

<listitem><para>Create a block device node if it does not

exist yet. If suffixed with <varname>+</varname> and a file

already exists where the device node is to be created, it

will be removed and be replaced by the device node. It is

recommended to suffix this entry with an exclamation mark to

only create static device nodes at boot, as udev will not

manage static device nodes that are created at runtime.

</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>C</varname></term>

<listitem><para>Recursively copy a file or directory, if the

destination files or directories do not exist yet. Note that

this command will not descend into subdirectories if the

destination directory already exists. Instead, the entire

copy operation is skipped. If the argument is omitted, files

from the source directory

<filename>/usr/share/factory/</filename> with the same name

are copied. Does not follow symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>x</varname></term>

<listitem><para>Ignore a path during cleaning. Use this type

to exclude paths from clean-up as controlled with the Age

parameter. Note that lines of this type do not influence the

effect of <varname>r</varname> or <varname>R</varname>

lines. Lines of this type accept shell-style globs in place

of normal path names. </para></listitem>

</varlistentry>

<varlistentry>

<term><varname>X</varname></term>

<listitem><para>Ignore a path during cleaning. Use this type

to exclude paths from clean-up as controlled with the Age

parameter. Unlike <varname>x</varname>, this parameter will

not exclude the content if path is a directory, but only

directory itself. Note that lines of this type do not

influence the effect of <varname>r</varname> or

<varname>R</varname> lines. Lines of this type accept

shell-style globs in place of normal path names.

</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>r</varname></term>

<listitem><para>Remove a file or directory if it exists.

This may not be used to remove non-empty directories, use

<varname>R</varname> for that. Lines of this type accept

shell-style globs in place of normal path

names. Does not follow symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>R</varname></term>

<listitem><para>Recursively remove a path and all its

subdirectories (if it is a directory). Lines of this type

accept shell-style globs in place of normal path

names. Does not follow symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>z</varname></term>

<listitem><para>Adjust the access mode, group and user, and

restore the SELinux security context of a file or directory,

if it exists. Lines of this type accept shell-style globs in

place of normal path names. Does not follow symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>Z</varname></term>

<listitem><para>Recursively set the access mode, group and

user, and restore the SELinux security context of a file or

directory if it exists, as well as of its subdirectories and

the files contained therein (if applicable). Lines of this

type accept shell-style globs in place of normal path

names. Does not follow symlinks. </para></listitem>

</varlistentry>

<varlistentry>

<term><varname>t</varname></term>

<listitem><para>Set extended attributes. Lines of this type

accept shell-style globs in place of normal path names.

This can be useful for setting SMACK labels. Does not follow

symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>T</varname></term>

<listitem><para>Recursively set extended attributes. Lines

of this type accept shell-style globs in place of normal

path names. This can be useful for setting SMACK

labels. Does not follow symlinks. </para></listitem>

</varlistentry>

<varlistentry>

<term><varname>h</varname></term>

<listitem><para>Set file/directory attributes. Lines of this type

accept shell-style globs in place of normal path names.</para>

<para>The format of the argument field is

<varname>[+-=][aAcCdDeijsStTu] </varname>. The prefix

<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

letters <literal>aAcCdDeijsStTu</literal> select the new

attributes for the files, see

<citerefentry><refentrytitle>chattr</refentrytitle>

<manvolnum>1</manvolnum></citerefentry> for further information.

</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

the attributes corresponding to the letters listed here. All

other attributes will be left untouched. Does not follow

symlinks.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>H</varname></term>

<listitem><para>Recursively set file/directory attributes. Lines

of this type accept shell-style globs in place of normal

path names. Does not follow symlinks.

</para></listitem>

</varlistentry>

<varlistentry>

<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

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

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

files. Does not follow symlinks.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>A</varname></term>

<term><varname>A+</varname></term>

<listitem><para>Same as <varname>a</varname> and

<varname>a+</varname>, but recursive. Does not follow

symlinks.</para></listitem>

</varlistentry>

</variablelist>

<para>If the exclamation mark is used, this line is only safe of

execute during boot, and can break a running system. Lines

without the exclamation mark are presumed to be safe to execute

at any time, e.g. on package upgrades.

<command>systemd-tmpfiles</command> will execute line with an

exclamation mark only if option <option>--boot</option> is

given.</para>

<para>For example:

<programlisting># Make sure these are created by default so that nobody else can

d /tmp/.X11-unix 1777 root root 10d

# 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>

</refsect2>

<refsect2>

<title>Path</title>

<para>The file system path specification supports simple

specifier expansion. The following expansions are

understood:</para>

<table>

<title>Specifiers available</title>

<tgroup cols='3' align='left' colsep='1' rowsep='1'>

<colspec colname="spec" />

<colspec colname="mean" />

<colspec colname="detail" />

<thead>

<row>

<entry>Specifier</entry>

<entry>Meaning</entry>

<entry>Details</entry>

</row>

</thead>

<tbody>

<row>

<entry><literal>%m</literal></entry>

<entry>Machine ID</entry>

<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>

</row>

<row>

<entry><literal>%b</literal></entry>

<entry>Boot ID</entry>

<entry>The boot ID of the running system, formatted as string. See <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry> for more information.</entry>

</row>

<row>

<entry><literal>%H</literal></entry>

<entry>Host name</entry>

<entry>The hostname of the running system.</entry>

</row>

<row>

<entry><literal>%v</literal></entry>

<entry>Kernel release</entry>

<entry>Identical to <command>uname -r</command> output.</entry>

</row>

<row>

<entry><literal>%%</literal></entry>

<entry>Escaped %</entry>

<entry>Single percent sign.</entry>

</row>

</tbody>

</tgroup>

</table>

</refsect2>

<refsect2>

<title>Mode</title>

<para>The file access mode to use when creating this file or

directory. If omitted or when set to <literal>-</literal>, the

default is used: 0755 for directories, 0644 for all other file

objects. For <varname>z</varname>, <varname>Z</varname> lines,

if omitted or when set to <literal>-</literal>, the file access

mode will not be modified. This parameter is ignored for

<varname>x</varname>, <varname>r</varname>,

<varname>R</varname>, <varname>L</varname>, <varname>t</varname>,

and <varname>a</varname> lines.</para>

<para>Optionally, if prefixed with <literal>~</literal>, the

access mode is masked based on the already set access bits for

existing file or directories: if the existing file has all

executable bits unset, all executable bits are removed from the

new access mode, too. Similarly, if all read bits are removed

from the old access mode, they will be removed from the new

access mode too, and if all write bits are removed, they will be

removed from the new access mode too. In addition, the

sticky/SUID/SGID bit is removed unless applied to a

directory. This functionality is particularly useful in

conjunction with <varname>Z</varname>.</para>

</refsect2>

<refsect2>

<title>UID, GID</title>

<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>,

<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>,

<varname>r</varname>, <varname>R</varname>,

<varname>L</varname>, <varname>t</varname>, and

<varname>a</varname> lines.</para>

</refsect2>

<refsect2>

<title>Age</title>

<para>The date field, when set, is used to decide what files to

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:

<constant>s</constant>,

<constant>m</constant> or <constant>min</constant>,

<constant>h</constant>,

<constant>d</constant>,

<constant>w</constant>,

<constant>ms</constant>,

<constant>us</constant>,

respectively meaning seconds, minutes, hours, days, weeks,

milliseconds, and microseconds. Full names of the time units can

be used too.

</para>

<para>If multiple integers and units are specified, the time

values are summed. If an integer is given without a unit,

<constant>s</constant> is assumed.

</para>

<para>When the age is set to zero, the files are cleaned

unconditionally.</para>

<para>The age field only applies to lines starting with

<varname>d</varname>, <varname>D</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

<literal>-</literal>, no automatic clean-up is done.</para>

<para>If the age field starts with a tilde character

<literal>~</literal>, the clean-up is only applied to files and

directories one level inside the directory specified, but not

the files and directories immediately inside it.</para>

</refsect2>

<refsect2>

<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

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

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>

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

set. Ignored for all other lines.</para>

</refsect2>

</refsect1>

<refsect1>

<title>Example</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>

<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>

<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>

<programlisting>d /var/tmp/abrt 0755 abrt abrt

x /var/tmp/abrt/*</programlisting>

</example>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry project='man-pages'><refentrytitle>attr</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry project='man-pages'><refentrytitle>getfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry project='man-pages'><refentrytitle>setfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry project='man-pages'><refentrytitle>setfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry project='man-pages'><refentrytitle>getfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry project='die-net'><refentrytitle>btrfs-subvolume</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

<citerefentry project='die-net'><refentrytitle>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry>

</para>

</refsect1>

</refentry>