os-release(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | SEE ALSO | NOTES | COLOPHON

OS-RELEASE(5)                  os-release                  OS-RELEASE(5)

NAME         top

       os-release, initrd-release - Operating system identification

SYNOPSIS         top

       /etc/os-release

       /usr/lib/os-release

       /etc/initrd-release

DESCRIPTION         top

       The /etc/os-release and /usr/lib/os-release files contain
       operating system identification data.

       The basic file format of os-release is a newline-separated list
       of environment-like shell-compatible variable assignments. It is
       possible to source the configuration from shell scripts, however,
       beyond mere variable assignments, no shell features are supported
       (this means variable expansion is explicitly not supported),
       allowing applications to read the file without implementing a
       shell compatible execution engine. Variable assignment values
       must be enclosed in double or single quotes if they include
       spaces, semicolons or other special characters outside of A–Z,
       a–z, 0–9. Shell special characters ("$", quotes, backslash,
       backtick) must be escaped with backslashes, following shell
       style. All strings should be in UTF-8 format, and non-printable
       characters should not be used. It is not supported to concatenate
       multiple individually quoted strings. Lines beginning with "#"
       shall be ignored as comments. Blank lines are permitted and
       ignored.

       The file /etc/os-release takes precedence over
       /usr/lib/os-release. Applications should check for the former,
       and exclusively use its data if it exists, and only fall back to
       /usr/lib/os-release if it is missing. Applications should not
       read data from both files at the same time.  /usr/lib/os-release
       is the recommended place to store OS release information as part
       of vendor trees.  /etc/os-release should be a relative symlink to
       /usr/lib/os-release, to provide compatibility with applications
       only looking at /etc/. A relative symlink instead of an absolute
       symlink is necessary to avoid breaking the link in a chroot or
       initrd environment such as dracut.

       os-release contains data that is defined by the operating system
       vendor and should generally not be changed by the administrator.

       As this file only encodes names and identifiers it should not be
       localized.

       The /etc/os-release and /usr/lib/os-release files might be
       symlinks to other files, but it is important that the file is
       available from earliest boot on, and hence must be located on the
       root file system.

       For a longer rationale for os-release please refer to the
       Announcement of /etc/os-release[1].

   /etc/initrd-release
       In the initrd[2], /etc/initrd-release plays the same role as
       os-release in the main system. Additionally, the presence of that
       file means that the system is in the initrd phase.
       /etc/os-release should be symlinked to /etc/initrd-release (or
       vice versa), so programs that only look for /etc/os-release (as
       described above) work correctly. The rest of this document that
       talks about os-release should be understood to apply to
       initrd-release too.

OPTIONS         top

       The following OS identifications parameters may be set using
       os-release:

   General information identifying the operating system
       NAME=
           A string identifying the operating system, without a version
           component, and suitable for presentation to the user. If not
           set, a default of "NAME=Linux" may be used.

           Examples: "NAME=Fedora", "NAME="Debian GNU/Linux"".

       ID=
           A lower-case string (no spaces or other characters outside of
           0–9, a–z, ".", "_" and "-") identifying the operating system,
           excluding any version information and suitable for processing
           by scripts or usage in generated filenames. If not set, a
           default of "ID=linux" may be used.

           Examples: "ID=fedora", "ID=debian".

       ID_LIKE=
           A space-separated list of operating system identifiers in the
           same syntax as the ID= setting. It should list identifiers of
           operating systems that are closely related to the local
           operating system in regards to packaging and programming
           interfaces, for example listing one or more OS identifiers
           the local OS is a derivative from. An OS should generally
           only list other OS identifiers it itself is a derivative of,
           and not any OSes that are derived from it, though symmetric
           relationships are possible. Build scripts and similar should
           check this variable if they need to identify the local
           operating system and the value of ID= is not recognized.
           Operating systems should be listed in order of how closely
           the local operating system relates to the listed ones,
           starting with the closest. This field is optional.

           Examples: for an operating system with "ID=centos", an
           assignment of "ID_LIKE="rhel fedora"" would be appropriate.
           For an operating system with "ID=ubuntu", an assignment of
           "ID_LIKE=debian" is appropriate.

       PRETTY_NAME=
           A pretty operating system name in a format suitable for
           presentation to the user. May or may not contain a release
           code name or OS version of some kind, as suitable. If not
           set, a default of "PRETTY_NAME="Linux"" may be used

           Example: "PRETTY_NAME="Fedora 17 (Beefy Miracle)"".

       CPE_NAME=
           A CPE name for the operating system, in URI binding syntax,
           following the Common Platform Enumeration Specification[3] as
           proposed by the NIST. This field is optional.

           Example: "CPE_NAME="cpe:/o:fedoraproject:fedora:17""

       VARIANT=
           A string identifying a specific variant or edition of the
           operating system suitable for presentation to the user. This
           field may be used to inform the user that the configuration
           of this system is subject to a specific divergent set of
           rules or default configuration settings. This field is
           optional and may not be implemented on all systems.

           Examples: "VARIANT="Server Edition"", "VARIANT="Smart
           Refrigerator Edition"".

           Note: this field is for display purposes only. The VARIANT_ID
           field should be used for making programmatic decisions.

       VARIANT_ID=
           A lower-case string (no spaces or other characters outside of
           0–9, a–z, ".", "_" and "-"), identifying a specific variant
           or edition of the operating system. This may be interpreted
           by other packages in order to determine a divergent default
           configuration. This field is optional and may not be
           implemented on all systems.

           Examples: "VARIANT_ID=server", "VARIANT_ID=embedded".

   Information about the version of the operating system
       VERSION=
           A string identifying the operating system version, excluding
           any OS name information, possibly including a release code
           name, and suitable for presentation to the user. This field
           is optional.

           Examples: "VERSION=17", "VERSION="17 (Beefy Miracle)"".

       VERSION_ID=
           A lower-case string (mostly numeric, no spaces or other
           characters outside of 0–9, a–z, ".", "_" and "-") identifying
           the operating system version, excluding any OS name
           information or release code name, and suitable for processing
           by scripts or usage in generated filenames. This field is
           optional.

           Examples: "VERSION_ID=17", "VERSION_ID=11.04".

       VERSION_CODENAME=
           A lower-case string (no spaces or other characters outside of
           0–9, a–z, ".", "_" and "-") identifying the operating system
           release code name, excluding any OS name information or
           release version, and suitable for processing by scripts or
           usage in generated filenames. This field is optional and may
           not be implemented on all systems.

           Examples: "VERSION_CODENAME=buster",
           "VERSION_CODENAME=xenial".

       BUILD_ID=
           A string uniquely identifying the system image originally
           used as the installation base. In most cases, VERSION_ID or
           IMAGE_ID+IMAGE_VERSION are updated when the entire system
           image is replaced during an update.  BUILD_ID may be used in
           distributions where the original installation image version
           is important: VERSION_ID would change during incremental
           system updates, but BUILD_ID would not. This field is
           optional.

           Examples: "BUILD_ID="2013-03-20.3"", "BUILD_ID=201303203".

       IMAGE_ID=
           A lower-case string (no spaces or other characters outside of
           0–9, a–z, ".", "_" and "-"), identifying a specific image of
           the operating system. This is supposed to be used for
           environments where OS images are prepared, built, shipped and
           updated as comprehensive, consistent OS images. This field is
           optional and may not be implemented on all systems, in
           particularly not on those that are not managed via images but
           put together and updated from individual packages and on the
           local system.

           Examples: "IMAGE_ID=vendorx-cashier-system",
           "IMAGE_ID=netbook-image".

       IMAGE_VERSION=
           A lower-case string (mostly numeric, no spaces or other
           characters outside of 0–9, a–z, ".", "_" and "-") identifying
           the OS image version. This is supposed to be used together
           with IMAGE_ID described above, to discern different versions
           of the same image.

           Examples: "IMAGE_VERSION=33", "IMAGE_VERSION=47.1rc1".

       To summarize: if the image updates are built and shipped as
       comprehensive units, IMAGE_ID+IMAGE_VERSION is the best fit.
       Otherwise, if updates eventually completely replace previously
       installed contents, as in a typical binary distribution,
       VERSION_ID should be used to identify major releases of the
       operating system.  BUILD_ID may be used instead or in addition to
       VERSION_ID when the original system image version is important.

   Presentation information and links
       HOME_URL=, DOCUMENTATION_URL=, SUPPORT_URL=, BUG_REPORT_URL=,
       PRIVACY_POLICY_URL=
           Links to resources on the Internet related to the operating
           system.  HOME_URL= should refer to the homepage of the
           operating system, or alternatively some homepage of the
           specific version of the operating system.  DOCUMENTATION_URL=
           should refer to the main documentation page for this
           operating system.  SUPPORT_URL= should refer to the main
           support page for the operating system, if there is any. This
           is primarily intended for operating systems which vendors
           provide support for.  BUG_REPORT_URL= should refer to the
           main bug reporting page for the operating system, if there is
           any. This is primarily intended for operating systems that
           rely on community QA.  PRIVACY_POLICY_URL= should refer to
           the main privacy policy page for the operating system, if
           there is any. These settings are optional, and providing only
           some of these settings is common. These URLs are intended to
           be exposed in "About this system" UIs behind links with
           captions such as "About this Operating System", "Obtain
           Support", "Report a Bug", or "Privacy Policy". The values
           should be in RFC3986 format[4], and should be "http:" or
           "https:" URLs, and possibly "mailto:" or "tel:". Only one URL
           shall be listed in each setting. If multiple resources need
           to be referenced, it is recommended to provide an online
           landing page linking all available resources.

           Examples: "HOME_URL="https://fedoraproject.org/"",
           "BUG_REPORT_URL="https://bugzilla.redhat.com/"".

       LOGO=
           A string, specifying the name of an icon as defined by
           freedesktop.org Icon Theme Specification[5]. This can be used
           by graphical applications to display an operating system's or
           distributor's logo. This field is optional and may not
           necessarily be implemented on all systems.

           Examples: "LOGO=fedora-logo",
           "LOGO=distributor-logo-opensuse"

       ANSI_COLOR=
           A suggested presentation color when showing the OS name on
           the console. This should be specified as string suitable for
           inclusion in the ESC [ m ANSI/ECMA-48 escape code for setting
           graphical rendition. This field is optional.

           Examples: "ANSI_COLOR="0;31"" for red, "ANSI_COLOR="1;34""
           for light blue, or "ANSI_COLOR="0;38;2;60;110;180"" for
           Fedora blue.

   Distribution-level defaults and metadata
       DEFAULT_HOSTNAME=
           A string specifying the hostname if hostname(5) is not
           present and no other configuration source specifies the
           hostname. Must be either a single DNS label (a string
           composed of 7-bit ASCII lower-case characters and no spaces
           or dots, limited to the format allowed for DNS domain name
           labels), or a sequence of such labels separated by single
           dots that forms a valid DNS FQDN. The hostname must be at
           most 64 characters, which is a Linux limitation (DNS allows
           longer names).

           See org.freedesktop.hostname1(5) for a description of how
           systemd-hostnamed.service(8) determines the fallback
           hostname.

       SYSEXT_LEVEL=
           A lower-case string (mostly numeric, no spaces or other
           characters outside of 0–9, a–z, ".", "_" and "-") identifying
           the operating system extensions support level, to indicate
           which extension images are supported. See: systemd-sysext(8))
           for more information.

           Examples: "SYSEXT_LEVEL=2", "SYSEXT_LEVEL=15.14".

   Notes
       If you are using this file to determine the OS or a specific
       version of it, use the ID and VERSION_ID fields, possibly with
       ID_LIKE as fallback for ID. When looking for an OS identification
       string for presentation to the user use the PRETTY_NAME field.

       Note that operating system vendors may choose not to provide
       version information, for example to accommodate for rolling
       releases. In this case, VERSION and VERSION_ID may be unset.
       Applications should not rely on these fields to be set.

       Operating system vendors may extend the file format and introduce
       new fields. It is highly recommended to prefix new fields with an
       OS specific name in order to avoid name clashes. Applications
       reading this file must ignore unknown fields.

       Example: "DEBIAN_BTS="debbugs://bugs.debian.org/"".

       Container and sandbox runtime managers may make the host's
       identification data available to applications by providing the
       host's /etc/os-release (if available, otherwise
       /usr/lib/os-release as a fallback) as /run/host/os-release.

EXAMPLES         top

       Example 1. os-release file for Fedora Workstation

           NAME=Fedora
           VERSION="32 (Workstation Edition)"
           ID=fedora
           VERSION_ID=32
           PRETTY_NAME="Fedora 32 (Workstation Edition)"
           ANSI_COLOR="0;38;2;60;110;180"
           LOGO=fedora-logo-icon
           CPE_NAME="cpe:/o:fedoraproject:fedora:32"
           HOME_URL="https://fedoraproject.org/"
           DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f32/system-administrators-guide/"
           SUPPORT_URL="https://fedoraproject.org/wiki/Communicating_and_getting_help"
           BUG_REPORT_URL="https://bugzilla.redhat.com/"
           REDHAT_BUGZILLA_PRODUCT="Fedora"
           REDHAT_BUGZILLA_PRODUCT_VERSION=32
           REDHAT_SUPPORT_PRODUCT="Fedora"
           REDHAT_SUPPORT_PRODUCT_VERSION=32
           PRIVACY_POLICY_URL="https://fedoraproject.org/wiki/Legal:PrivacyPolicy"
           VARIANT="Workstation Edition"
           VARIANT_ID=workstation

       Example 2. Reading os-release in sh(1)

           #!/bin/sh -eu

           test -e /etc/os-release && os_release='/etc/os-release' || os_release='/usr/lib/os-release'
           . "${os_release}"

           echo "Running on ${PRETTY_NAME:-Linux}"

           if [ "${ID:-linux}" = "debian" ] || [ "${ID_LIKE#*debian*}" != "${ID_LIKE}" ]; then
               echo "Looks like Debian!"
           fi

       Example 3. Reading os-release in python(1)

           #!/usr/bin/python

           import ast
           import re
           import sys

           def read_os_release():
               try:
                   filename = '/etc/os-release'
                   f = open(filename)
               except FileNotFoundError:
                   filename = '/usr/lib/os-release'
                   f = open(filename)

               for line_number, line in enumerate(f):
                   line = line.rstrip()
                   if not line or line.startswith('#'):
                       continue
                   if m := re.match(r'([A-Z][A-Z_0-9]+)=(.*)', line):
                       name, val = m.groups()
                       if val and val[0] in '"\'':
                           val = ast.literal_eval(val)
                       yield name, val
                   else:
                       print(f'{filename}:{line_number + 1}: bad line {line!r}',
                             file=sys.stderr)

           os_release = dict(read_os_release())

           pretty_name = os_release.get('PRETTY_NAME', 'Linux')
           print(f'Running on {pretty_name}')

           if 'debian' in [os_release.get('ID', 'linux'),
                           *os_release.get('ID_LIKE', '').split()]:
               print('Looks like Debian!')

SEE ALSO         top

       systemd(1), lsb_release(1), hostname(5), machine-id(5),
       machine-info(5)

NOTES         top

        1. Announcement of /etc/os-release
           http://0pointer.de/blog/projects/os-release

        2. initrd
           https://www.kernel.org/doc/html/latest/admin-guide/initrd.html

        3. Common Platform Enumeration Specification
           http://scap.nist.gov/specifications/cpe/

        4. RFC3986 format
           https://tools.ietf.org/html/rfc3986

        5. freedesktop.org Icon Theme Specification
           http://standards.freedesktop.org/icon-theme-spec/latest

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2021-06-20.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-06-19.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 249                                                OS-RELEASE(5)

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