man/os-release.xml

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  11   Copyright 2010 Lennart Poettering
  12
  13   systemd is free software; you can redistribute it and/or modify it
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  26
  27 <refentry id="os-release">
  28   <refentryinfo>
  29     <title>os-release</title>
  30     <productname>systemd</productname>
  31
  32     <authorgroup>
  33       <author>
  34         <contrib>Developer</contrib>
  35         <firstname>Lennart</firstname>
  36         <surname>Poettering</surname>
  37         <email>lennart@poettering.net</email>
  38       </author>
  39     </authorgroup>
  40   </refentryinfo>
  41
  42   <refmeta>
  43     <refentrytitle>os-release</refentrytitle>
  44     <manvolnum>5</manvolnum>
  45   </refmeta>
  46
  47   <refnamediv>
  48     <refname>os-release</refname>
  49     <refpurpose>Operating system identification</refpurpose>
  50   </refnamediv>
  51
  52   <refsynopsisdiv>
  53     <para><filename>/etc/os-release</filename></para>
  54     <para><filename>/usr/lib/os-release</filename></para>
  55   </refsynopsisdiv>
  56
  57   <refsect1>
  58     <title>Description</title>
  59
  60     <para>The <filename>/etc/os-release</filename> and
  61     <filename>/usr/lib/os-release</filename> files contain operating
  62     system identification data.</para>
  63
  64     <para>The basic file format of <filename>os-release</filename> is
  65     a newline-separated list of environment-like shell-compatible
  66     variable assignments. It is possible to source the configuration
  67     from shell scripts, however, beyond mere variable assignments, no
  68     shell features are supported (this means variable expansion is
  69     explicitly not supported), allowing applications to read the file
  70     without implementing a shell compatible execution engine. Variable
  71     assignment values must be enclosed in double or single quotes if
  72     they include spaces, semicolons or other special characters
  73     outside of A-Z, a-z, 0-9. Shell special characters ("$", quotes,
  74     backslash, backtick) must be escaped with backslashes, following
  75     shell style. All strings should be in UTF-8 format, and
  76     non-printable characters should not be used. It is not supported
  77     to concatenate multiple individually quoted strings. Lines
  78     beginning with "#" shall be ignored as comments.</para>
  79
  80     <para>The file <filename>/etc/os-release</filename> takes
  81     precedence over <filename>/usr/lib/os-release</filename>.
  82     Applications should check for the former, and exclusively use its
  83     data if it exists, and only fall back to
  84     <filename>/usr/lib/os-release</filename> if it is missing.
  85     Applications should not read data from both files at the same
  86     time. <filename>/usr/lib/os-release</filename> is the recommended
  87     place to store OS release information as part of vendor trees.
  88     <filename>/etc/os-release</filename> should be a relative symlink
  89     to <filename>/usr/lib/os-release</filename>, to provide
  90     compatibility with applications only looking at
  91     <filename>/etc</filename>. A relative symlink instead of an
  92     absolute symlink is necessary to avoid breaking the link in a
  93     chroot or initrd environment such as dracut.</para>
  94
  95     <para><filename>os-release</filename> contains data that is
  96     defined by the operating system vendor and should generally not be
  97     changed by the administrator.</para>
  98
  99     <para>As this file only encodes names and identifiers it should
 100     not be localized.</para>
 101
 102     <para>The <filename>/etc/os-release</filename> and
 103     <filename>/usr/lib/os-release</filename> files might be symlinks
 104     to other files, but it is important that the file is available
 105     from earliest boot on, and hence must be located on the root file
 106     system.</para>
 107
 108     <para>For a longer rationale for <filename>os-release</filename>
 109     please refer to the <ulink
 110     url="http://0pointer.de/blog/projects/os-release">Announcement of <filename>/etc/os-release</filename></ulink>.</para>
 111   </refsect1>
 112
 113   <refsect1>
 114     <title>Options</title>
 115
 116     <para>The following OS identifications parameters may be set using
 117     <filename>os-release</filename>:</para>
 118
 119     <variablelist>
 120
 121       <varlistentry>
 122         <term><varname>NAME=</varname></term>
 123
 124         <listitem><para>A string identifying the operating system,
 125         without a version component, and suitable for presentation to
 126         the user. If not set, defaults to
 127         <literal>NAME=Linux</literal>. Example:
 128         <literal>NAME=Fedora</literal> or <literal>NAME="Debian
 129         GNU/Linux"</literal>.</para></listitem>
 130       </varlistentry>
 131
 132       <varlistentry>
 133         <term><varname>VERSION=</varname></term>
 134
 135         <listitem><para>A string identifying the operating system
 136         version, excluding any OS name information, possibly including
 137         a release code name, and suitable for presentation to the
 138         user. This field is optional. Example:
 139         <literal>VERSION=17</literal> or <literal>VERSION="17 (Beefy
 140         Miracle)"</literal>.</para></listitem>
 141       </varlistentry>
 142
 143       <varlistentry>
 144         <term><varname>ID=</varname></term>
 145
 146         <listitem><para>A lower-case string (no spaces or other
 147         characters outside of 0-9, a-z, ".", "_" and "-") identifying
 148         the operating system, excluding any version information and
 149         suitable for processing by scripts or usage in generated
 150         filenames. If not set, defaults to
 151         <literal>ID=linux</literal>. Example:
 152         <literal>ID=fedora</literal> or
 153         <literal>ID=debian</literal>.</para></listitem>
 154       </varlistentry>
 155
 156       <varlistentry>
 157         <term><varname>ID_LIKE=</varname></term>
 158
 159         <listitem><para>A space-separated list of operating system
 160         identifiers in the same syntax as the <varname>ID=</varname>
 161         setting. It should list identifiers of operating systems that
 162         are closely related to the local operating system in regards
 163         to packaging and programming interfaces, for example listing
 164         one or more OS identifiers the local OS is a derivative from.
 165         An OS should generally only list other OS identifiers it
 166         itself is a derivative of, and not any OSes that are derived
 167         from it, though symmetric relationships are possible. Build
 168         scripts and similar should check this variable if they need to
 169         identify the local operating system and the value of
 170         <varname>ID=</varname> is not recognized. Operating systems
 171         should be listed in order of how closely the local operating
 172         system relates to the listed ones, starting with the closest.
 173         This field is optional. Example: for an operating system with
 174         <literal>ID=centos</literal>, an assignment of
 175         <literal>ID_LIKE="rhel fedora"</literal> would be appropriate.
 176         For an operating system with <literal>ID=ubuntu</literal>, an
 177         assignment of <literal>ID_LIKE=debian</literal> is
 178         appropriate.</para></listitem>
 179       </varlistentry>
 180
 181       <varlistentry>
 182         <term><varname>VERSION_ID=</varname></term>
 183
 184         <listitem><para>A lower-case string (mostly numeric, no spaces
 185         or other characters outside of 0-9, a-z, ".", "_" and "-")
 186         identifying the operating system version, excluding any OS
 187         name information or release code name, and suitable for
 188         processing by scripts or usage in generated filenames. This
 189         field is optional. Example: <literal>VERSION_ID=17</literal>
 190         or <literal>VERSION_ID=11.04</literal>.</para></listitem>
 191       </varlistentry>
 192
 193       <varlistentry>
 194         <term><varname>PRETTY_NAME=</varname></term>
 195
 196         <listitem><para>A pretty operating system name in a format
 197         suitable for presentation to the user. May or may not contain
 198         a release code name or OS version of some kind, as suitable.
 199         If not set, defaults to
 200         <literal>PRETTY_NAME="Linux"</literal>. Example:
 201         <literal>PRETTY_NAME="Fedora 17 (Beefy
 202         Miracle)"</literal>.</para></listitem>
 203       </varlistentry>
 204
 205       <varlistentry>
 206         <term><varname>ANSI_COLOR=</varname></term>
 207
 208         <listitem><para>A suggested presentation color when showing
 209         the OS name on the console. This should be specified as string
 210         suitable for inclusion in the ESC [ m ANSI/ECMA-48 escape code
 211         for setting graphical rendition. This field is optional.
 212         Example: <literal>ANSI_COLOR="0;31"</literal> for red, or
 213         <literal>ANSI_COLOR="1;34"</literal> for light
 214         blue.</para></listitem>
 215       </varlistentry>
 216
 217       <varlistentry>
 218         <term><varname>CPE_NAME=</varname></term>
 219
 220         <listitem><para>A CPE name for the operating system, following
 221         the <ulink url="https://cpe.mitre.org/specification/">Common
 222         Platform Enumeration Specification</ulink> as proposed by the
 223         MITRE Corporation. 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>