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<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

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. 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>

<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.</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.</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.</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>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.</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.</para></listitem>

</varlistentry>

<varlistentry>

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

<listitem><para>Recursively

copy a file or directory, if

the destination files or

directories don't 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.</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.</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.</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.

</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.</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 -, 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> 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 then all

executable bits are removed from the new

access mode, too. Similar, 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/gid 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 -, the file

ownership will not be modified. These

parameters are ignored for

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

<varname>R</varname>, <varname>L</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:</para>

<variablelist>

<varlistentry>

<term><varname>s</varname></term>

<term><varname>min</varname></term>

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

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

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

<term><varname>ms</varname></term>

<term><varname>m</varname></term>

<term><varname>us</varname></term></varlistentry>

</variablelist>

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

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

s 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>, 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. 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</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>

</para>

</refsect1>

</refentry>