man/os-release.xml

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