man/os-release.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   4
   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   This file is part of systemd.
   9
  10   Copyright 2010 Lennart Poettering
  11 -->
  12
  13 <refentry id="os-release">
  14   <refentryinfo>
  15     <title>os-release</title>
  16     <productname>systemd</productname>
  17
  18     <authorgroup>
  19       <author>
  20         <contrib>Developer</contrib>
  21         <firstname>Lennart</firstname>
  22         <surname>Poettering</surname>
  23         <email>lennart@poettering.net</email>
  24       </author>
  25     </authorgroup>
  26   </refentryinfo>
  27
  28   <refmeta>
  29     <refentrytitle>os-release</refentrytitle>
  30     <manvolnum>5</manvolnum>
  31   </refmeta>
  32
  33   <refnamediv>
  34     <refname>os-release</refname>
  35     <refpurpose>Operating system identification</refpurpose>
  36   </refnamediv>
  37
  38   <refsynopsisdiv>
  39     <para><filename>/etc/os-release</filename></para>
  40     <para><filename>/usr/lib/os-release</filename></para>
  41   </refsynopsisdiv>
  42
  43   <refsect1>
  44     <title>Description</title>
  45
  46     <para>The <filename>/etc/os-release</filename> and
  47     <filename>/usr/lib/os-release</filename> files contain operating
  48     system identification data.</para>
  49
  50     <para>The basic file format of <filename>os-release</filename> is
  51     a newline-separated list of environment-like shell-compatible
  52     variable assignments. It is possible to source the configuration
  53     from shell scripts, however, beyond mere variable assignments, no
  54     shell features are supported (this means variable expansion is
  55     explicitly not supported), allowing applications to read the file
  56     without implementing a shell compatible execution engine. Variable
  57     assignment values must be enclosed in double or single quotes if
  58     they include spaces, semicolons or other special characters
  59     outside of A–Z, a–z, 0–9. Shell special characters ("$", quotes,
  60     backslash, backtick) must be escaped with backslashes, following
  61     shell style. All strings should be in UTF-8 format, and
  62     non-printable characters should not be used. It is not supported
  63     to concatenate multiple individually quoted strings. Lines
  64     beginning with "#" shall be ignored as comments. Blank lines are
  65     permitted and ignored.</para>
  66
  67     <para>The file <filename>/etc/os-release</filename> takes
  68     precedence over <filename>/usr/lib/os-release</filename>.
  69     Applications should check for the former, and exclusively use its
  70     data if it exists, and only fall back to
  71     <filename>/usr/lib/os-release</filename> if it is missing.
  72     Applications should not read data from both files at the same
  73     time. <filename>/usr/lib/os-release</filename> is the recommended
  74     place to store OS release information as part of vendor trees.
  75     <filename>/etc/os-release</filename> should be a relative symlink
  76     to <filename>/usr/lib/os-release</filename>, to provide
  77     compatibility with applications only looking at
  78     <filename>/etc</filename>. A relative symlink instead of an
  79     absolute symlink is necessary to avoid breaking the link in a
  80     chroot or initrd environment such as dracut.</para>
  81
  82     <para><filename>os-release</filename> contains data that is
  83     defined by the operating system vendor and should generally not be
  84     changed by the administrator.</para>
  85
  86     <para>As this file only encodes names and identifiers it should
  87     not be localized.</para>
  88
  89     <para>The <filename>/etc/os-release</filename> and
  90     <filename>/usr/lib/os-release</filename> files might be symlinks
  91     to other files, but it is important that the file is available
  92     from earliest boot on, and hence must be located on the root file
  93     system.</para>
  94
  95     <para>For a longer rationale for <filename>os-release</filename>
  96     please refer to the <ulink
  97     url="http://0pointer.de/blog/projects/os-release">Announcement of <filename>/etc/os-release</filename></ulink>.</para>
  98   </refsect1>
  99
 100   <refsect1>
 101     <title>Options</title>
 102
 103     <para>The following OS identifications parameters may be set using
 104     <filename>os-release</filename>:</para>
 105
 106     <variablelist>
 107
 108       <varlistentry>
 109         <term><varname>NAME=</varname></term>
 110
 111         <listitem><para>A string identifying the operating system,
 112         without a version component, and suitable for presentation to
 113         the user. If not set, defaults to
 114         <literal>NAME=Linux</literal>. Example:
 115         <literal>NAME=Fedora</literal> or <literal>NAME="Debian
 116         GNU/Linux"</literal>.</para></listitem>
 117       </varlistentry>
 118
 119       <varlistentry>
 120         <term><varname>VERSION=</varname></term>
 121
 122         <listitem><para>A string identifying the operating system
 123         version, excluding any OS name information, possibly including
 124         a release code name, and suitable for presentation to the
 125         user. This field is optional. Example:
 126         <literal>VERSION=17</literal> or <literal>VERSION="17 (Beefy
 127         Miracle)"</literal>.</para></listitem>
 128       </varlistentry>
 129
 130       <varlistentry>
 131         <term><varname>ID=</varname></term>
 132
 133         <listitem><para>A lower-case string (no spaces or other
 134         characters outside of 0–9, a–z, ".", "_" and "-") identifying
 135         the operating system, excluding any version information and
 136         suitable for processing by scripts or usage in generated
 137         filenames. If not set, defaults to
 138         <literal>ID=linux</literal>. Example:
 139         <literal>ID=fedora</literal> or
 140         <literal>ID=debian</literal>.</para></listitem>
 141       </varlistentry>
 142
 143       <varlistentry>
 144         <term><varname>ID_LIKE=</varname></term>
 145
 146         <listitem><para>A space-separated list of operating system
 147         identifiers in the same syntax as the <varname>ID=</varname>
 148         setting. It should list identifiers of operating systems that
 149         are closely related to the local operating system in regards
 150         to packaging and programming interfaces, for example listing
 151         one or more OS identifiers the local OS is a derivative from.
 152         An OS should generally only list other OS identifiers it
 153         itself is a derivative of, and not any OSes that are derived
 154         from it, though symmetric relationships are possible. Build
 155         scripts and similar should check this variable if they need to
 156         identify the local operating system and the value of
 157         <varname>ID=</varname> is not recognized. Operating systems
 158         should be listed in order of how closely the local operating
 159         system relates to the listed ones, starting with the closest.
 160         This field is optional. Example: for an operating system with
 161         <literal>ID=centos</literal>, an assignment of
 162         <literal>ID_LIKE="rhel fedora"</literal> would be appropriate.
 163         For an operating system with <literal>ID=ubuntu</literal>, an
 164         assignment of <literal>ID_LIKE=debian</literal> is
 165         appropriate.</para></listitem>
 166       </varlistentry>
 167
 168       <varlistentry>
 169         <term><varname>VERSION_CODENAME=</varname></term>
 170
 171         <listitem><para>
 172         A lower-case string (no spaces or other characters outside of
 173         0–9, a–z, ".", "_" and "-") identifying the operating system
 174         release code name, excluding any OS name information or
 175         release version, and suitable for processing by scripts or
 176         usage in generated filenames. This field is optional and may
 177         not be implemented on all systems.
 178         Examples:
 179         <literal>VERSION_CODENAME=buster</literal>,
 180         <literal>VERSION_CODENAME=xenial</literal>
 181         </para></listitem>
 182       </varlistentry>
 183
 184       <varlistentry>
 185         <term><varname>VERSION_ID=</varname></term>
 186
 187         <listitem><para>A lower-case string (mostly numeric, no spaces
 188         or other characters outside of 0–9, a–z, ".", "_" and "-")
 189         identifying the operating system version, excluding any OS
 190         name information or release code name, and suitable for
 191         processing by scripts or usage in generated filenames. This
 192         field is optional. Example: <literal>VERSION_ID=17</literal>
 193         or <literal>VERSION_ID=11.04</literal>.</para></listitem>
 194       </varlistentry>
 195
 196       <varlistentry>
 197         <term><varname>PRETTY_NAME=</varname></term>
 198
 199         <listitem><para>A pretty operating system name in a format
 200         suitable for presentation to the user. May or may not contain
 201         a release code name or OS version of some kind, as suitable.
 202         If not set, defaults to
 203         <literal>PRETTY_NAME="Linux"</literal>. Example:
 204         <literal>PRETTY_NAME="Fedora 17 (Beefy
 205         Miracle)"</literal>.</para></listitem>
 206       </varlistentry>
 207
 208       <varlistentry>
 209         <term><varname>ANSI_COLOR=</varname></term>
 210
 211         <listitem><para>A suggested presentation color when showing
 212         the OS name on the console. This should be specified as string
 213         suitable for inclusion in the ESC [ m ANSI/ECMA-48 escape code
 214         for setting graphical rendition. This field is optional.
 215         Example: <literal>ANSI_COLOR="0;31"</literal> for red, or
 216         <literal>ANSI_COLOR="1;34"</literal> for light
 217         blue.</para></listitem>
 218       </varlistentry>
 219
 220       <varlistentry>
 221         <term><varname>CPE_NAME=</varname></term>
 222
 223         <listitem><para>A CPE name for the operating system, in URI
 224         binding syntax, following the
 225         <ulink url="http://scap.nist.gov/specifications/cpe/">Common
 226         Platform Enumeration Specification</ulink> as proposed by the
 227         NIST. This field is optional. Example:
 228         <literal>CPE_NAME="cpe:/o:fedoraproject:fedora:17"</literal>
 229         </para></listitem>
 230       </varlistentry>
 231
 232       <varlistentry>
 233         <term><varname>HOME_URL=</varname></term>
 234         <term><varname>SUPPORT_URL=</varname></term>
 235         <term><varname>BUG_REPORT_URL=</varname></term>
 236         <term><varname>PRIVACY_POLICY_URL=</varname></term>
 237
 238         <listitem><para>Links to resources on the Internet related the
 239         operating system. <varname>HOME_URL=</varname> should refer to
 240         the homepage of the operating system, or alternatively some
 241         homepage of the specific version of the operating system.
 242         <varname>SUPPORT_URL=</varname> should refer to the main
 243         support page for the operating system, if there is any. This
 244         is primarily intended for operating systems which vendors
 245         provide support for. <varname>BUG_REPORT_URL=</varname> should
 246         refer to the main bug reporting page for the operating system,
 247         if there is any. This is primarily intended for operating
 248         systems that rely on community QA.
 249         <varname>PRIVACY_POLICY_URL=</varname> should refer to the
 250         main privacy policy page for the operation system, if there is
 251         any. These settings are optional, and providing only some of
 252         these settings is common. These URLs are intended to be
 253         exposed in "About this system" UIs behind links with captions
 254         such as "About this Operating System", "Obtain Support",
 255         "Report a Bug", or "Privacy Policy". The values should be in
 256         <ulink url="https://tools.ietf.org/html/rfc3986">RFC3986
 257         format</ulink>, and should be <literal>http:</literal> or
 258         <literal>https:</literal> URLs, and possibly
 259         <literal>mailto:</literal> or <literal>tel:</literal>. Only
 260         one URL shall be listed in each setting. If multiple resources
 261         need to be referenced, it is recommended to provide an online
 262         landing page linking all available resources. Examples:
 263         <literal>HOME_URL="https://fedoraproject.org/"</literal> and
 264         <literal>BUG_REPORT_URL="https://bugzilla.redhat.com/"</literal></para></listitem>
 265       </varlistentry>
 266
 267       <varlistentry>
 268         <term><varname>BUILD_ID=</varname></term>
 269
 270         <listitem><para>A string uniquely identifying the system image
 271         used as the origin for a distribution (it is not updated with
 272         system updates). The field can be identical between different
 273         VERSION_IDs as BUILD_ID is an only a unique identifier to a
 274         specific version. Distributions that release each update as a
 275         new version would only need to use VERSION_ID as each build is
 276         already distinct based on the VERSION_ID. This field is
 277         optional. Example: <literal>BUILD_ID="2013-03-20.3"</literal>
 278         or <literal>BUILD_ID=201303203</literal>.
 279
 280         </para></listitem>
 281       </varlistentry>
 282
 283       <varlistentry>
 284         <term><varname>VARIANT=</varname></term>
 285
 286         <listitem><para>
 287         A string identifying a specific variant or edition of the
 288         operating system suitable for presentation to the user. This
 289         field may be used to inform the user that the configuration of
 290         this system is subject to a specific divergent set of rules or
 291         default configuration settings. This field is optional and may
 292         not be implemented on all systems.
 293         Examples:
 294         <literal>VARIANT="Server Edition"</literal>,
 295         <literal>VARIANT="Smart Refrigerator Edition"</literal>
 296         Note: this field is for display purposes only. The
 297         <varname>VARIANT_ID</varname> field should be used for making
 298         programmatic decisions.
 299         </para></listitem>
 300       </varlistentry>
 301
 302       <varlistentry>
 303         <term><varname>VARIANT_ID=</varname></term>
 304
 305         <listitem><para>
 306         A lower-case string (no spaces or other characters outside of
 307         0–9, a–z, ".", "_" and "-"), identifying a specific variant or
 308         edition of the operating system. This may be interpreted by
 309         other packages in order to determine a divergent default
 310         configuration. This field is optional and may not be
 311         implemented on all systems.
 312         Examples:
 313         <literal>VARIANT_ID=server</literal>,
 314         <literal>VARIANT_ID=embedded</literal>
 315         </para></listitem>
 316       </varlistentry>
 317
 318     </variablelist>
 319
 320     <para>If you are reading this file from C code or a shell script
 321     to determine the OS or a specific version of it, use the
 322     <varname>ID</varname> and <varname>VERSION_ID</varname> fields,
 323     possibly with <varname>ID_LIKE</varname> as fallback for
 324     <varname>ID</varname>. When looking for an OS identification
 325     string for presentation to the user use the
 326     <varname>PRETTY_NAME</varname> field.</para>
 327
 328     <para>Note that operating system vendors may choose not to provide
 329     version information, for example to accommodate for rolling
 330     releases. In this case, <varname>VERSION</varname> and
 331     <varname>VERSION_ID</varname> may be unset. Applications should
 332     not rely on these fields to be set.</para>
 333
 334     <para>Operating system vendors may extend the file
 335     format and introduce new fields. It is highly
 336     recommended to prefix new fields with an OS specific
 337     name in order to avoid name clashes. Applications
 338     reading this file must ignore unknown fields. Example:
 339     <literal>DEBIAN_BTS="debbugs://bugs.debian.org/"</literal></para>
 340   </refsect1>
 341
 342   <refsect1>
 343     <title>Example</title>
 344
 345     <programlisting>NAME=Fedora
 346 VERSION="17 (Beefy Miracle)"
 347 ID=fedora
 348 VERSION_ID=17
 349 PRETTY_NAME="Fedora 17 (Beefy Miracle)"
 350 ANSI_COLOR="0;34"
 351 CPE_NAME="cpe:/o:fedoraproject:fedora:17"
 352 HOME_URL="https://fedoraproject.org/"
 353 BUG_REPORT_URL="https://bugzilla.redhat.com/"</programlisting>
 354   </refsect1>
 355
 356   <refsect1>
 357       <title>See Also</title>
 358       <para>
 359         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 360         <citerefentry project='die-net'><refentrytitle>lsb_release</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 361         <citerefentry><refentrytitle>hostname</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 362         <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 363         <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 364       </para>
 365   </refsect1>
 366
 367 </refentry>