man/os-release.xml

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