man/os-release.xml

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