идентификация операционной системы (Operating system identification)
Описание (Description)
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
/etc/initrd-release
In the initrd
The rest of this document that talks about os-release should be
understood to apply to initrd-release too.
/usr/lib/extension-release.d/extension-release.IMAGE
/usr/lib/extension-release.d/extension-release.IMAGE plays the
same role for extension images as os-release for the main system,
and follows the syntax and rules as described in the Portable
Services Documentation
In the extension-release.IMAGE filename, the IMAGE part must
exactly match the file name of the containing image with the
suffix removed. In case it is not possible to guarantee that an
image file name is stable and doesn't change between the build
and the deployment phases, it is possible to relax this check: if
exactly one file whose name matches "extension-release.*" is
present in this directory, and the file is tagged with a
user.extension-release.strict xattr(7) set to the string "0", it
will be used instead.
The rest of this document that talks about os-release should be
understood to apply to extension-release too.
