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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
Copyright 2014 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="file-hierarchy">
<refentryinfo>
<title>file-hierarchy</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>file-hierarchy</refentrytitle>
<manvolnum>7</manvolnum>
</refmeta>
<refnamediv>
<refname>file-hierarchy</refname>
<refpurpose>File system hierarchy overview</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>Operating systems using the
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
system and service manager are organized based on a
file system hierarchy inspired by UNIX, more
specifically the hierarchy described in the <ulink
url="http://refspecs.linuxfoundation.org/FHS_2.3/fhs-2.3.html">File
System Hierarchy</ulink> specification and
<citerefentry><refentrytitle>hier</refentrytitle><manvolnum>7</manvolnum></citerefentry>. This
manual page describes a more minimal, modernized
subset of these specifications that defines more
strictly the suggestions and restrictions systemd
makes on the file system hierarchy.</para>
<para>Many of the paths described here are queriable
with the
<citerefentry><refentrytitle>systemd-path</refentrytitle><manvolnum>1</manvolnum></citerefentry>
tool.</para>
</refsect1>
<refsect1>
<title>General Structure</title>
<variablelist>
<varlistentry>
<term><filename>/</filename></term>
<listitem><para>The file system
root. Usually writable, but this is
not required. Possibly a temporary
file system (<literal>tmpfs</literal>). Not shared with
other hosts (unless read-only).
</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/boot</filename></term>
<listitem><para>The boot partition
used for bringing up the system. On
EFI systems this is possibly the EFI
System Partition, also see
<citerefentry><refentrytitle>systemd-efi-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>. This
directory is usually strictly local
to the host, and should be considered
read-only, except when a new kernel or
boot loader is installed. This
directory only exists on systems that
run on physical or emulated hardware
that requires boot
loaders.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/etc</filename></term>
<listitem><para>System-specific
configuration. This directory may or
may not be read-only. Frequently, this
directory is pre-populated with
vendor-supplied configuration files,
but applications should not make
assumptions about this directory
being fully populated or populated at
all, and should fall back to defaults
if configuration is missing.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/home</filename></term>
<listitem><para>The location for
normal user's home
directories. Possibly shared with
other systems, and never
read-only. This directory should only
be used for normal users, never for
system users. This directory and
possibly the directories contained
within it might only become available
or writable in late boot or even only
after user authentication. This directory
might be placed on limited-functionality
network file systems, hence
applications should not assume the
full set of file API is available on
this directory. Applications should
generally not reference this directory
directly, but via the per-user
<varname>$HOME</varname> environment
variable, or via the home directory
field of the user
database.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/root</filename></term>
<listitem><para>The home directory of
the root user. The root user's home
directory is located outside of
<filename>/home</filename> in order to
make sure the root user may log in
even without <filename>/home</filename>
being available and
mounted.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/srv</filename></term>
<listitem><para>The place to store
general server payload, managed by the
administrator. No restrictions are
made how this directory is organized
internally. Generally writable, and
possibly shared among systems. This
directory might become available or
writable only very late during
boot.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/tmp</filename></term>
<listitem><para>The place for small
temporary files. This directory is
usually mounted as
a <literal>tmpfs</literal> instance, and
should hence not be used for larger
files. (Use
<filename>/var/tmp</filename> for
larger files.) Since the directory is
accessible to other users of the
system it is essential that this
directory is only written to with the
<citerefentry><refentrytitle>mkstemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>mkdtemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>
and related calls. This directory is
usually flushed at boot-up. Also,
files that are not accessed within a
certain time are usually automatically
deleted. If applications find the
environment variable
<varname>$TMPDIR</varname> set they
should prefer using the directory
specified in it over directly
referencing
<filename>/tmp</filename> (see <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
and
<ulink url="http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03">IEEE Std 1003.1</ulink> for details).</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Runtime Data</title>
<variablelist>
<varlistentry>
<term><filename>/run</filename></term>
<listitem><para>A
<literal>tmpfs</literal> file system
for system packages to place runtime
data in. This directory is flushed on
boot, and generally writable for
privileged programs
only. Always writable.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/run/log</filename></term>
<listitem><para>Runtime system
logs. System components may place
private logs in this directory. Always
writable, even when
<filename>/var/log</filename> might
not be accessible
yet.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/run/user</filename></term>
<listitem><para>Contains per-user
runtime directories, each usually
individually mounted
<literal>tmpfs</literal>
instances. Always writable, flushed at
each reboot and when the user logs
out. User code should not reference
this directory directly, but via the
<varname>$XDG_RUNTIME_DIR</varname>
environment variable, as documented in
the <ulink
url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG
Base Directory
Specification</ulink>.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Vendor-supplied Operating System Resources</title>
<variablelist>
<varlistentry>
<term><filename>/usr</filename></term>
<listitem><para>Vendor-supplied
operating system resources. Usually
read-only, but this is not
required. Possibly shared between
multiple hosts. This directory should
not be modified by the administrator,
except when installing or removing
vendor-supplied
packages.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/bin</filename></term>
<listitem><para>Binaries and
executables for user commands, that
shall appear in the
<varname>$PATH</varname> search
path. It is recommended not to place
binaries in this directory that are
not useful for invocation from a shell
(such as daemon binaries); these
should be placed in a subdirectory of
<filename>/usr/lib</filename>
instead.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/include</filename></term>
<listitem><para>C and C++ API header
files of system
libraries.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/lib</filename></term>
<listitem><para>Static, private vendor
data that is compatible with all
architectures (though not necessarily
architecture-independent). Note that
this includes internal executables or
other binaries that are not regularly
invoked from a shell. Such binaries
may be for any architecture supported
by the system. Do not place public
libraries in this directory, use
<varname>$libdir</varname> (see
below), instead.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/lib/<replaceable>arch-id</replaceable></filename></term>
<listitem><para>Location for placing
dynamic libraries, also called <varname>$libdir</varname>.
The architecture identifier to use is defined on <ulink
url="https://wiki.debian.org/Multiarch/Tuples">Multiarch Architecture Specifiers (Tuples)</ulink>
list. Legacy locations of <varname>$libdir</varname> are
<filename>/usr/lib</filename>,
<filename>/usr/lib64</filename>.
This directory should not
be used for package-specific data,
unless this data is
architecture-dependent, too. To query
<varname>$libdir</varname> for the
primary architecture of the system,
invoke:
<programlisting># pkg-config --variable=libdir systemd</programlisting> or
<programlisting># systemd-path system-library-arch</programlisting>
</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/share</filename></term>
<listitem><para>Resources shared
between multiple packages, such as
documentation, man pages, time zone
information, fonts and other
resources. Usually, the precise
location and format of files stored
below this directory is subject to
specifications that ensure
interoperability.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/share/doc</filename></term>
<listitem><para>Documentation for the
operating system or system
packages.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/share/factory/etc</filename></term>
<listitem><para>Repository for
vendor-supplied default configuration
files. This directory should be
populated with pristine vendor versions
of all configuration files that may be
placed in
<filename>/etc</filename>. This is
useful to compare the local
configuration of a system with vendor
defaults and to populate the local
configuration with
defaults.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/usr/share/factory/var</filename></term>
<listitem><para>Similar to
<filename>/usr/share/factory/etc</filename>
but for vendor versions of files in
the variable, persistent data
directory
<filename>/var</filename>.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Persistent Variable System Data</title>
<variablelist>
<varlistentry>
<term><filename>/var</filename></term>
<listitem><para>Persistent, variable
system data. Must be writable. This
directory might be pre-populated with
vendor-supplied data, but applications
should be able to reconstruct
necessary files and directories in
this subhierarchy should they be
missing, as the system might start up
without this directory being
populated. Persistency is recommended,
but optional, to support ephemeral
systems. This directory might become
available or writable only very late
during boot. Components that are
required to operate during early boot
hence shall not unconditionally rely
on this directory.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/var/cache</filename></term>
<listitem><para>Persistent system
cache data. System components may
place non-essential data in this
directory. Flushing this directory
should have no effect on operation of
programs, except for increased
runtimes necessary to rebuild these
caches.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/var/lib</filename></term>
<listitem><para>Persistent system
data. System components may
place private data in this
directory.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/var/log</filename></term>
<listitem><para>Persistent system
logs. System components may place
private logs in this directory, though
it is recommended to do most logging
via the
<citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
and
<citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>3</manvolnum></citerefentry>
calls.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/var/spool</filename></term>
<listitem><para>Persistent system
spool data, such as printer or mail
queues.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/var/tmp</filename></term>
<listitem><para>The place for larger
and persistent temporary files. In
contrast to <filename>/tmp</filename>
this directory is usually mounted from
a persistent physical file system and
can thus accept larger files. (Use
<filename>/tmp</filename> for smaller
files.) This directory is generally
not flushed at boot-up, but time-based
cleanup of files that have not been
accessed for a certain time is
applied. The same security
restrictions as with
<filename>/tmp</filename> apply, and
hence only
<citerefentry><refentrytitle>mkstemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>mkdtemp</refentrytitle><manvolnum>3</manvolnum></citerefentry>
or similar calls should be used to
make use of this directory. If
applications find the environment
variable <varname>$TMPDIR</varname>
set they should prefer using the
directory specified in it over
directly referencing
<filename>/var/tmp</filename> (see <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
for details).
</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Virtual Kernel and API File Systems</title>
<variablelist>
<varlistentry>
<term><filename>/dev</filename></term>
<listitem><para>The root directory for
device nodes. Usually this directory
is mounted as a
<literal>devtmpfs</literal> instance,
but might be of a different type in
sandboxed/containerized setups. This
directory is managed jointly by the
kernel and
<citerefentry><refentrytitle>systemd-udevd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
and should not be written to by other
components. A number of special
purpose virtual file systems might be
mounted below this
directory.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/dev/shm</filename></term>
<listitem><para>Place for POSIX shared
memory segments, as created via
<citerefentry><refentrytitle>shm_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This
directory is flushed on boot, and is a
<literal>tmpfs</literal> file
system. Since all users have write
access to this directory, special care
should be taken to avoid name clashes
and vulnerabilities. For normal users,
shared memory segments in this
directory are usually deleted when the
user logs out. Usually it is a better
idea to use memory mapped files in
<filename>/run</filename> (for system
programs) or
<varname>$XDG_RUNTIME_DIR</varname>
(for user programs) instead of POSIX
shared memory segments, since those
directories are not world-writable and
hence not vulnerable to
security-sensitive name
clashes.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/proc</filename></term>
<listitem><para>A virtual kernel file
system exposing the process list and
other functionality. This file system
is mostly an API to interface with the
kernel and not a place where normal
files may be stored. For details, see
<citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>. A
number of special purpose virtual file
systems might be mounted below this
directory.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/proc/sys</filename></term>
<listitem><para>A hierarchy below
<filename>/proc</filename> that
exposes a number of kernel
tunables. The primary way to configure
the settings in this API file tree is
via
<citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
files. In sandboxed/containerized
setups this directory is generally
mounted read-only.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/sys</filename></term>
<listitem><para>A virtual kernel file
system exposing discovered devices and
other functionality. This file system
is mostly an API to interface with the
kernel and not a place where normal
files may be stored. In
sandboxed/containerized setups this
directory is generally mounted
read-only. A number of special purpose
virtual file systems might be mounted
below this
directory.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Compatibility Symlinks</title>
<variablelist>
<varlistentry>
<term><filename>/bin</filename></term>
<term><filename>/sbin</filename></term>
<term><filename>/usr/sbin</filename></term>
<listitem><para>These compatibility
symlinks point to
<filename>/usr/bin</filename>,
ensuring that scripts and binaries
referencing these legacy paths
correctly find their binaries.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/lib</filename></term>
<listitem><para>This compatibility
symlink points to
<filename>/usr/lib</filename>,
ensuring that programs referencing
this legacy path correctly find
their resources.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/lib64</filename></term>
<listitem><para>On some architecture
ABIs this compatibility symlink points
to <varname>$libdir</varname>,
ensuring that binaries referencing
this legacy path correctly find their
dynamic loader. This symlink only
exists on architectures whose ABI
places the dynamic loader in this
path.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>/var/run</filename></term>
<listitem><para>This compatibility
symlink points to
<filename>/run</filename>, ensuring
that programs referencing this legacy
path correctly find their runtime
data.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Home Directory</title>
<para>User applications may want to place files and
directories in the user's home directory. They should
follow the following basic structure. Note that some
of these directories are also standardized (though
more weakly) by the <ulink
url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG
Base Directory Specification</ulink>. Additional
locations for high-level user resources are defined by
<ulink
url="http://www.freedesktop.org/wiki/Software/xdg-user-dirs/">xdg-user-dirs</ulink>.</para>
<variablelist>
<varlistentry>
<term><filename>~/.cache</filename></term>
<listitem><para>Persistent user cache
data. User programs may place
non-essential data in this
directory. Flushing this directory
should have no effect on operation of
programs, except for increased
runtimes necessary to rebuild these
caches. If an application finds
<varname>$XDG_CACHE_HOME</varname> set
is should use the directory specified
in it instead of this
directory.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>~/.config</filename></term>
<listitem><para>Application
configuration and state. When a new
user is created this directory will be
empty or not exist at
all. Applications should fall back to
defaults should their configuration or
state in this directory be missing. If
an application finds
<varname>$XDG_CONFIG_HOME</varname> set
is should use the directory specified
in it instead of this
directory.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>~/.local/bin</filename></term>
<listitem><para>Executables that shall
appear in the user's
<varname>$PATH</varname> search
path. It is recommended not to place
executables in this directory that are
not useful for invocation from a
shell; these should be placed in a
subdirectory of
<filename>~/.local/lib</filename>
instead. Care should be taken when
placing architecture-dependent
binaries in this place which might be
problematic if the home directory is
shared between multiple hosts with
different
architectures.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>~/.local/lib</filename></term>
<listitem><para>Static, private vendor
data that is compatible with all
architectures.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>~/.local/lib/<replaceable>arch-id</replaceable></filename></term>
<listitem><para>Location for placing
public dynamic libraries. The architecture
identifier to use, is defined on <ulink
url="https://wiki.debian.org/Multiarch/Tuples">Multiarch Architecture Specifiers (Tuples)</ulink>
list.</para></listitem>
</varlistentry>
<varlistentry>
<term><filename>~/.local/share</filename></term>
<listitem><para>Resources shared
between multiple packages, such as
fonts or artwork. Usually, the precise
location and format of files stored
below this directory is subject to
specifications that ensure
interoperability. If
an application finds
<varname>$XDG_DATA_HOME</varname> set
is should use the directory specified
in it instead of this
directory.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Unprivileged Write Access</title>
<para>Unprivileged processes generally lack
write access to most of the hierarchy.</para>
<para>The exceptions for normal users are
<filename>/tmp</filename>,
<filename>/var/tmp</filename>,
<filename>/dev/shm</filename>, as well as the home
directory <varname>$HOME</varname> (usually found
below <filename>/home</filename>) and the runtime
directory <varname>$XDG_RUNTIME_DIR</varname> (found
below <filename>/run/user</filename>) of the
user, which are all writable.</para>
<para>For unprivileged system processes only
<filename>/tmp</filename>,
<filename>/var/tmp</filename> and
<filename>/dev/shm</filename> are writable. If an
unprivileged system process needs a private, writable
directory in <filename>/var</filename> or
<filename>/run</filename>, it is recommended to either
create it before dropping privileges in the daemon
code, to create it via
<citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
fragments during boot, or via the
<varname>RuntimeDirectory=</varname> directive of
service units (see
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for details).</para>
</refsect1>
<refsect1>
<title>Node Types</title>
<para>Unix file systems support different types of file
nodes, including regular files, directories, symlinks,
character and block device nodes, sockets and FIFOs.</para>
<para>It is strongly recommended that
<filename>/dev</filename> is the only location below
which device nodes shall be placed. Similar,
<filename>/run</filename> shall be the only location
to place sockets and FIFOs. Regular files,
directories and symlinks may be used in all
directories.</para>
</refsect1>
<refsect1>
<title>System Packages</title>
<para>Developers of system packages should follow
strict rules when placing their own files in the file
system. The following table lists recommended
locations for specific types of files supplied by the
vendor.</para>
<table>
<title>System Package Vendor Files Locations</title>
<tgroup cols='2' align='left' colsep='1' rowsep='1'>
<colspec colname="directory" />
<colspec colname="purpose" />
<thead>
<row>
<entry>Directory</entry>
<entry>Purpose</entry>
</row>
</thead>
<tbody>
<row>
<entry><filename>/usr/bin</filename></entry>
<entry>Package executables that shall appear in the <varname>$PATH</varname> executable search path, compiled for any of the supported architectures compatible with the operating system. It is not recommended to place internal binaries or binaries that are not commonly invoked from the shell in this directory, such as daemon binaries. As this directory is shared with most other packages of the system special care should be taken to pick unique names for files placed here, that are unlikely to clash with other package's files.</entry>
</row>
<row>
<entry><filename>/usr/lib/<replaceable>arch-id</replaceable></filename></entry>
<entry>Public shared libraries of the package. As above, be careful with using too generic names, and pick unique names for your libraries to place here to avoid name clashes.</entry>
</row>
<row>
<entry><filename>/usr/lib/<replaceable>package</replaceable></filename></entry>
<entry>Private, static vendor resources of the package, including private binaries and libraries, or any other kind of read-only vendor data.</entry>
</row>
<row>
<entry><filename>/usr/lib/<replaceable>arch-id</replaceable>/<replaceable>package</replaceable></filename></entry>
<entry>Private other vendor resources of the package that are architecture-specific and cannot be shared between architectures. Note that this generally does not include private executables since binaries of a specific architecture may be freely invoked from any other supported system architecture.</entry>
</row>
<row>
<entry><filename>/usr/include/<replaceable>package</replaceable></filename></entry>
<entry>Public C/C++ APIs of public shared libraries of the package.</entry>
</row>
</tbody>
</tgroup>
</table>
<para>Additional static vendor files may be installed
in the <filename>/usr/share</filename> hierarchy, to
the locations defined by the various relevant
specifications.</para>
<para>During runtime and for local configuration and
state additional directories are defined:</para>
<table>
<title>System Package Variable Files Locations</title>
<tgroup cols='2' align='left' colsep='1' rowsep='1'>
<colspec colname="directory" />
<colspec colname="purpose" />
<thead>
<row>
<entry>Directory</entry>
<entry>Purpose</entry>
</row>
</thead>
<tbody>
<row>
<entry><filename>/etc/<replaceable>package</replaceable></filename></entry>
<entry>System-specific configuration for the package. It is recommended to default to safe fallbacks if this configuration is missing, if this is possible. Alternatively, a <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> fragment may be used to copy or symlink the necessary files and directories from <filename>/usr/share/factory</filename> during boot, via the <literal>L</literal> or <literal>C</literal> directives.</entry>
</row>
<row>
<entry><filename>/run/<replaceable>package</replaceable></filename></entry>
<entry>Runtime data for the package. Packages must be able to create the necessary subdirectories in this tree on their own, since the directory is flushed automatically on boot. Alternatively, a <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> fragment may be used to create the necessary directories during boot. Alternatively, the <varname>RuntimeDirectory=</varname> directive of service units may be used (see <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details.)</entry>
</row>
<row>
<entry><filename>/run/log/<replaceable>package</replaceable></filename></entry>
<entry>Runtime log data for the package. As above, the package needs to make sure to create this directory if necessary, as it will be flushed on every boot.</entry>
</row>
<row>
<entry><filename>/var/cache/<replaceable>package</replaceable></filename></entry>
<entry>Persistent cache data of the package. If this directory is flushed the application should work correctly on next invocation, though possibly slowed down due to the need to rebuild any local cache files. The application must be capable of recreating this directory should it be missing and necessary.</entry>
</row>
<row>
<entry><filename>/var/lib/<replaceable>package</replaceable></filename></entry>
<entry>Persistent private data of the package. This is the primary place to put persistent data that does not fall into the other categories listed. Packages should be able to create the necessary subdirectories in this tree on their own, since the directory might be missing on boot. Alternatively, a <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> fragment may be used to create the necessary directories during boot.</entry>
</row>
<row>
<entry><filename>/var/log/<replaceable>package</replaceable></filename></entry>
<entry>Persistent log data of the package. As above, the package should make sure to create this directory if necessary, as it might be missing.</entry>
</row>
<row>
<entry><filename>/var/spool/<replaceable>package</replaceable></filename></entry>
<entry>Persistent spool/queue data of the package. As above, the package should make sure to create this directory if necessary, as it might be missing.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
<title>User Packages</title>
<para>Programs running in user context should follow
strict rules when placing their own files in the
user's home directory. The following table lists
recommended locations in the home directory for
specific types of files supplied by the vendor if the
application is installed in the home directory. (Note
however, that user applications installed system-wide
should follow the rules outlined above regarding
placing vendor files.)</para>
<table>
<title>User Package Vendor File Locations</title>
<tgroup cols='2' align='left' colsep='1' rowsep='1'>
<colspec colname="directory" />
<colspec colname="purpose" />
<thead>
<row>
<entry>Directory</entry>
<entry>Purpose</entry>
</row>
</thead>
<tbody>
<row>
<entry><filename>~/.local/bin</filename></entry>
<entry>Package executables that shall appear in the <varname>$PATH</varname> executable search path. It is not recommended to place internal executables or executables that are not commonly invoked from the shell in this directory, such as daemon executables. As this directory is shared with most other packages of the user special care should be taken to pick unique names for files placed here, that are unlikely to clash with other package's files.</entry>
</row>
<row>
<entry><filename>~/.local/lib/<replaceable>arch-id</replaceable></filename></entry>
<entry>Public shared libraries of the package. As above, be careful with using too generic names, and pick unique names for your libraries to place here to avoid name clashes.</entry>
</row>
<row>
<entry><filename>~/.local/lib/<replaceable>package</replaceable></filename></entry>
<entry>Private, static vendor resources of the package, compatible wih any architecture, or any other kind of read-only vendor data.</entry>
</row>
<row>
<entry><filename>~/.local/lib/<replaceable>arch-id</replaceable>/<replaceable>package</replaceable></filename></entry>
<entry>Private other vendor resources of the package that are architecture-specific and cannot be shared between architectures.</entry>
</row>
</tbody>
</tgroup>
</table>
<para>Additional static vendor files may be installed
in the <filename>~/.local/share</filename> hierarchy,
to the locations defined by the various relevant
specifications.</para>
<para>During runtime and for local configuration and
state additional directories are defined:</para>
<table>
<title>User Package Variable File Locations</title>
<tgroup cols='2' align='left' colsep='1' rowsep='1'>
<colspec colname="directory" />
<colspec colname="purpose" />
<thead>
<row>
<entry>Directory</entry>
<entry>Purpose</entry>
</row>
</thead>
<tbody>
<row>
<entry><filename>~/.config/<replaceable>package</replaceable></filename></entry>
<entry>User-specific configuration and state for the package. It is required to default to safe fallbacks if this configuration is missing.</entry>
</row>
<row>
<entry><filename><varname>$XDG_RUNTIME_DIR</varname>/<replaceable>package</replaceable></filename></entry>
<entry>User runtime data for the package.</entry>
</row>
<row>
<entry><filename>~/.cache/<replaceable>package</replaceable></filename></entry>
<entry>Persistent cache data of the package. If this directory is flushed the application should work correctly on next invocation, though possibly slowed down due to the need to rebuild any local cache files. The application must be capable of recreating this directory should it be missing and necessary.</entry>
</row>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>hier</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-path</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-efi-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
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