man/os-release.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   Copyright 2010 Lennart Poettering
   9 -->
  10
  11 <refentry id="os-release">
  12   <refentryinfo>
  13     <title>os-release</title>
  14     <productname>systemd</productname>
  15
  16     <authorgroup>
  17       <author>
  18         <contrib>Developer</contrib>
  19         <firstname>Lennart</firstname>
  20         <surname>Poettering</surname>
  21         <email>lennart@poettering.net</email>
  22       </author>
  23     </authorgroup>
  24   </refentryinfo>
  25
  26   <refmeta>
  27     <refentrytitle>os-release</refentrytitle>
  28     <manvolnum>5</manvolnum>
  29   </refmeta>
  30
  31   <refnamediv>
  32     <refname>os-release</refname>
  33     <refpurpose>Operating system identification</refpurpose>
  34   </refnamediv>
  35
  36   <refsynopsisdiv>
  37     <para><filename>/etc/os-release</filename></para>
  38     <para><filename>/usr/lib/os-release</filename></para>
  39   </refsynopsisdiv>
  40
  41   <refsect1>
  42     <title>Description</title>
  43
  44     <para>The <filename>/etc/os-release</filename> and
  45     <filename>/usr/lib/os-release</filename> files contain operating
  46     system identification data.</para>
  47
  48     <para>The basic file format of <filename>os-release</filename> is
  49     a newline-separated list of environment-like shell-compatible
  50     variable assignments. It is possible to source the configuration
  51     from shell scripts, however, beyond mere variable assignments, no
  52     shell features are supported (this means variable expansion is
  53     explicitly not supported), allowing applications to read the file
  54     without implementing a shell compatible execution engine. Variable
  55     assignment values must be enclosed in double or single quotes if
  56     they include spaces, semicolons or other special characters
  57     outside of A–Z, a–z, 0–9. Shell special characters ("$", quotes,
  58     backslash, backtick) must be escaped with backslashes, following
  59     shell style. All strings should be in UTF-8 format, and
  60     non-printable characters should not be used. It is not supported
  61     to concatenate multiple individually quoted strings. Lines
  62     beginning with "#" shall be ignored as comments. Blank lines are
  63     permitted and ignored.</para>
  64
  65     <para>The file <filename>/etc/os-release</filename> takes
  66     precedence over <filename>/usr/lib/os-release</filename>.
  67     Applications should check for the former, and exclusively use its
  68     data if it exists, and only fall back to
  69     <filename>/usr/lib/os-release</filename> if it is missing.
  70     Applications should not read data from both files at the same
  71     time. <filename>/usr/lib/os-release</filename> is the recommended
  72     place to store OS release information as part of vendor trees.
  73     <filename>/etc/os-release</filename> should be a relative symlink
  74     to <filename>/usr/lib/os-release</filename>, to provide
  75     compatibility with applications only looking at
  76     <filename>/etc</filename>. A relative symlink instead of an
  77     absolute symlink is necessary to avoid breaking the link in a
  78     chroot or initrd environment such as dracut.</para>
  79
  80     <para><filename>os-release</filename> contains data that is
  81     defined by the operating system vendor and should generally not be
  82     changed by the administrator.</para>
  83
  84     <para>As this file only encodes names and identifiers it should
  85     not be localized.</para>
  86
  87     <para>The <filename>/etc/os-release</filename> and
  88     <filename>/usr/lib/os-release</filename> files might be symlinks
  89     to other files, but it is important that the file is available
  90     from earliest boot on, and hence must be located on the root file
  91     system.</para>
  92
  93     <para>For a longer rationale for <filename>os-release</filename>
  94     please refer to the <ulink
  95     url="http://0pointer.de/blog/projects/os-release">Announcement of <filename>/etc/os-release</filename></ulink>.</para>
  96   </refsect1>
  97
  98   <refsect1>
  99     <title>Options</title>
 100
 101     <para>The following OS identifications parameters may be set using
 102     <filename>os-release</filename>:</para>
 103
 104     <variablelist>
 105
 106       <varlistentry>
 107         <term><varname>NAME=</varname></term>
 108
 109         <listitem><para>A string identifying the operating system,
 110         without a version component, and suitable for presentation to
 111         the user. If not set, defaults to
 112         <literal>NAME=Linux</literal>. Example:
 113         <literal>NAME=Fedora</literal> or <literal>NAME="Debian
 114         GNU/Linux"</literal>.</para></listitem>
 115       </varlistentry>
 116
 117       <varlistentry>
 118         <term><varname>VERSION=</varname></term>
 119
 120         <listitem><para>A string identifying the operating system
 121         version, excluding any OS name information, possibly including
 122         a release code name, and suitable for presentation to the
 123         user. This field is optional. Example:
 124         <literal>VERSION=17</literal> or <literal>VERSION="17 (Beefy
 125         Miracle)"</literal>.</para></listitem>
 126       </varlistentry>
 127
 128       <varlistentry>
 129         <term><varname>ID=</varname></term>
 130
 131         <listitem><para>A lower-case string (no spaces or other
 132         characters outside of 0–9, a–z, ".", "_" and "-") identifying
 133         the operating system, excluding any version information and
 134         suitable for processing by scripts or usage in generated
 135         filenames. If not set, defaults to
 136         <literal>ID=linux</literal>. Example:
 137         <literal>ID=fedora</literal> or
 138         <literal>ID=debian</literal>.</para></listitem>
 139       </varlistentry>
 140
 141       <varlistentry>
 142         <term><varname>ID_LIKE=</varname></term>
 143
 144         <listitem><para>A space-separated list of operating system
 145         identifiers in the same syntax as the <varname>ID=</varname>
 146         setting. It should list identifiers of operating systems that
 147         are closely related to the local operating system in regards
 148         to packaging and programming interfaces, for example listing
 149         one or more OS identifiers the local OS is a derivative from.
 150         An OS should generally only list other OS identifiers it
 151         itself is a derivative of, and not any OSes that are derived
 152         from it, though symmetric relationships are possible. Build
 153         scripts and similar should check this variable if they need to
 154         identify the local operating system and the value of
 155         <varname>ID=</varname> is not recognized. Operating systems
 156         should be listed in order of how closely the local operating
 157         system relates to the listed ones, starting with the closest.
 158         This field is optional. Example: for an operating system with
 159         <literal>ID=centos</literal>, an assignment of
 160         <literal>ID_LIKE="rhel fedora"</literal> would be appropriate.
 161         For an operating system with <literal>ID=ubuntu</literal>, an
 162         assignment of <literal>ID_LIKE=debian</literal> is
 163         appropriate.</para></listitem>
 164       </varlistentry>
 165
 166       <varlistentry>
 167         <term><varname>VERSION_CODENAME=</varname></term>
 168
 169         <listitem><para>
 170         A lower-case string (no spaces or other characters outside of
 171         0–9, a–z, ".", "_" and "-") identifying the operating system
 172         release code name, excluding any OS name information or
 173         release version, and suitable for processing by scripts or
 174         usage in generated filenames. This field is optional and may
 175         not be implemented on all systems.
 176         Examples:
 177         <literal>VERSION_CODENAME=buster</literal>,
 178         <literal>VERSION_CODENAME=xenial</literal>
 179         </para></listitem>
 180       </varlistentry>
 181
 182       <varlistentry>
 183         <term><varname>VERSION_ID=</varname></term>
 184
 185         <listitem><para>A lower-case string (mostly numeric, no spaces
 186         or other characters outside of 0–9, a–z, ".", "_" and "-")
 187         identifying the operating system version, excluding any OS
 188         name information or release code name, and suitable for
 189         processing by scripts or usage in generated filenames. This
 190         field is optional. Example: <literal>VERSION_ID=17</literal>
 191         or <literal>VERSION_ID=11.04</literal>.</para></listitem>
 192       </varlistentry>
 193
 194       <varlistentry>
 195         <term><varname>PRETTY_NAME=</varname></term>
 196
 197         <listitem><para>A pretty operating system name in a format
 198         suitable for presentation to the user. May or may not contain
 199         a release code name or OS version of some kind, as suitable.
 200         If not set, defaults to
 201         <literal>PRETTY_NAME="Linux"</literal>. Example:
 202         <literal>PRETTY_NAME="Fedora 17 (Beefy
 203         Miracle)"</literal>.</para></listitem>
 204       </varlistentry>
 205
 206       <varlistentry>
 207         <term><varname>ANSI_COLOR=</varname></term>
 208
 209         <listitem><para>A suggested presentation color when showing
 210         the OS name on the console. This should be specified as string
 211         suitable for inclusion in the ESC [ m ANSI/ECMA-48 escape code
 212         for setting graphical rendition. This field is optional.
 213         Example: <literal>ANSI_COLOR="0;31"</literal> for red, or
 214         <literal>ANSI_COLOR="1;34"</literal> for light
 215         blue.</para></listitem>
 216       </varlistentry>
 217
 218       <varlistentry>
 219         <term><varname>CPE_NAME=</varname></term>
 220
 221         <listitem><para>A CPE name for the operating system, in URI
 222         binding syntax, following the
 223         <ulink url="http://scap.nist.gov/specifications/cpe/">Common
 224         Platform Enumeration Specification</ulink> as proposed by the
 225         NIST. This field is optional. Example:
 226         <literal>CPE_NAME="cpe:/o:fedoraproject:fedora:17"</literal>
 227         </para></listitem>
 228       </varlistentry>
 229
 230       <varlistentry>
 231         <term><varname>HOME_URL=</varname></term>
 232         <term><varname>SUPPORT_URL=</varname></term>
 233         <term><varname>BUG_REPORT_URL=</varname></term>
 234         <term><varname>PRIVACY_POLICY_URL=</varname></term>
 235
 236         <listitem><para>Links to resources on the Internet related the
 237         operating system. <varname>HOME_URL=</varname> should refer to
 238         the homepage of the operating system, or alternatively some
 239         homepage of the specific version of the operating system.
 240         <varname>SUPPORT_URL=</varname> should refer to the main
 241         support page for the operating system, if there is any. This
 242         is primarily intended for operating systems which vendors
 243         provide support for. <varname>BUG_REPORT_URL=</varname> should
 244         refer to the main bug reporting page for the operating system,
 245         if there is any. This is primarily intended for operating
 246         systems that rely on community QA.
 247         <varname>PRIVACY_POLICY_URL=</varname> should refer to the
 248         main privacy policy page for the operation system, if there is
 249         any. These settings are optional, and providing only some of
 250         these settings is common. These URLs are intended to be
 251         exposed in "About this system" UIs behind links with captions
 252         such as "About this Operating System", "Obtain Support",
 253         "Report a Bug", or "Privacy Policy". The values should be in
 254         <ulink url="https://tools.ietf.org/html/rfc3986">RFC3986
 255         format</ulink>, and should be <literal>http:</literal> or
 256         <literal>https:</literal> URLs, and possibly
 257         <literal>mailto:</literal> or <literal>tel:</literal>. Only
 258         one URL shall be listed in each setting. If multiple resources
 259         need to be referenced, it is recommended to provide an online
 260         landing page linking all available resources. Examples:
 261         <literal>HOME_URL="https://fedoraproject.org/"</literal> and
 262         <literal>BUG_REPORT_URL="https://bugzilla.redhat.com/"</literal></para></listitem>
 263       </varlistentry>
 264
 265       <varlistentry>
 266         <term><varname>BUILD_ID=</varname></term>
 267
 268         <listitem><para>A string uniquely identifying the system image
 269         used as the origin for a distribution (it is not updated with
 270         system updates). The field can be identical between different
 271         VERSION_IDs as BUILD_ID is an only a unique identifier to a
 272         specific version. Distributions that release each update as a
 273         new version would only need to use VERSION_ID as each build is
 274         already distinct based on the VERSION_ID. This field is
 275         optional. Example: <literal>BUILD_ID="2013-03-20.3"</literal>
 276         or <literal>BUILD_ID=201303203</literal>.
 277
 278         </para></listitem>
 279       </varlistentry>
 280
 281       <varlistentry>
 282         <term><varname>VARIANT=</varname></term>
 283
 284         <listitem><para>
 285         A string identifying a specific variant or edition of the
 286         operating system suitable for presentation to the user. This
 287         field may be used to inform the user that the configuration of
 288         this system is subject to a specific divergent set of rules or
 289         default configuration settings. This field is optional and may
 290         not be implemented on all systems.
 291         Examples:
 292         <literal>VARIANT="Server Edition"</literal>,
 293         <literal>VARIANT="Smart Refrigerator Edition"</literal>
 294         Note: this field is for display purposes only. The
 295         <varname>VARIANT_ID</varname> field should be used for making
 296         programmatic decisions.
 297         </para></listitem>
 298       </varlistentry>
 299
 300       <varlistentry>
 301         <term><varname>VARIANT_ID=</varname></term>
 302
 303         <listitem><para>
 304         A lower-case string (no spaces or other characters outside of
 305         0–9, a–z, ".", "_" and "-"), identifying a specific variant or
 306         edition of the operating system. This may be interpreted by
 307         other packages in order to determine a divergent default
 308         configuration. This field is optional and may not be
 309         implemented on all systems.
 310         Examples:
 311         <literal>VARIANT_ID=server</literal>,
 312         <literal>VARIANT_ID=embedded</literal>
 313         </para></listitem>
 314       </varlistentry>
 315
 316     </variablelist>
 317
 318     <para>If you are reading this file from C code or a shell script
 319     to determine the OS or a specific version of it, use the
 320     <varname>ID</varname> and <varname>VERSION_ID</varname> fields,
 321     possibly with <varname>ID_LIKE</varname> as fallback for
 322     <varname>ID</varname>. When looking for an OS identification
 323     string for presentation to the user use the
 324     <varname>PRETTY_NAME</varname> field.</para>
 325
 326     <para>Note that operating system vendors may choose not to provide
 327     version information, for example to accommodate for rolling
 328     releases. In this case, <varname>VERSION</varname> and
 329     <varname>VERSION_ID</varname> may be unset. Applications should
 330     not rely on these fields to be set.</para>
 331
 332     <para>Operating system vendors may extend the file
 333     format and introduce new fields. It is highly
 334     recommended to prefix new fields with an OS specific
 335     name in order to avoid name clashes. Applications
 336     reading this file must ignore unknown fields. Example:
 337     <literal>DEBIAN_BTS="debbugs://bugs.debian.org/"</literal></para>
 338   </refsect1>
 339
 340   <refsect1>
 341     <title>Example</title>
 342
 343     <programlisting>NAME=Fedora
 344 VERSION="17 (Beefy Miracle)"
 345 ID=fedora
 346 VERSION_ID=17
 347 PRETTY_NAME="Fedora 17 (Beefy Miracle)"
 348 ANSI_COLOR="0;34"
 349 CPE_NAME="cpe:/o:fedoraproject:fedora:17"
 350 HOME_URL="https://fedoraproject.org/"
 351 BUG_REPORT_URL="https://bugzilla.redhat.com/"</programlisting>
 352   </refsect1>
 353
 354   <refsect1>
 355       <title>See Also</title>
 356       <para>
 357         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 358         <citerefentry project='die-net'><refentrytitle>lsb_release</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 359         <citerefentry><refentrytitle>hostname</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 360         <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 361         <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 362       </para>
 363   </refsect1>
 364
 365 </refentry>