X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fos-release.xml;h=b4cbeba39558f6f6ca86776a85ff8e061a87a600;hp=45babd61b9de168549751b1e5a9bc40f517910ea;hb=de59d29e8abc32ff8e5de6a36ddf9d04d63ccb47;hpb=f0b647223ded79068dd1d92da329d2ea95527590 diff --git a/man/os-release.xml b/man/os-release.xml index 45babd61b..b4cbeba39 100644 --- a/man/os-release.xml +++ b/man/os-release.xml @@ -49,49 +49,72 @@ /etc/os-release + /usr/lib/os-release Description - The /etc/os-release file - contains operating system identification data. + 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 + 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 should be enclosed - in double or single quotes if they include spaces, + 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. All strings should be in UTF-8 format, and - non-printable characters should not be used. If double - or single quotes or backslashes are to be used within - variable assignments they should be escaped with - backslashes, following shell style. It is not - supported to concatenate multiple individually quoted - strings. Lines beginning with "#" shall be ignored as - comments. - - /etc/os-release contains - data that is defined by the operating system vendor - and should not be changed by the administrator. + 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. + + 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 file /etc/os-release might - be a symlink to another file, but it is important that + 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 - /etc/os-release please refer to + os-release please refer to the Announcement of /etc/os-release. @@ -100,7 +123,7 @@ Options The following OS identifications parameters may be set using - /etc/os-release: + os-release: @@ -110,7 +133,7 @@ A string identifying the operating system, without a version component, and suitable for - presentation to the user. If not set + presentation to the user. If not set, defaults to NAME=Linux. Example: NAME=Fedora or @@ -142,8 +165,8 @@ identifying the operating system, excluding any version information and suitable for processing by scripts or - usage in generated file names. If not - set defaults to + usage in generated filenames. If not + set, defaults to ID=linux. Example: ID=fedora or ID=debian. @@ -155,7 +178,7 @@ A space-separated list of operating system identifiers in the same syntax as the - ID= setting. Should + ID= setting. It should list identifiers of operating systems that are closely related to the local operating system in regards to @@ -165,8 +188,8 @@ OS is a derivative from. An OS should generally only list other OS identifiers it itself is a derivative - from, and not any OSes that - are derived from it, but symmetric + 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 @@ -179,11 +202,11 @@ closest. This field is optional. Example: for an operating system with - ID=centos an + ID=centos, an assignment of ID_LIKE="rhel fedora" would be appropriate. For an operating system - with ID=ubuntu an + with ID=ubuntu, an assignment of ID_LIKE=debian is appropriate. @@ -199,7 +222,7 @@ system version, excluding any OS name information or release code name, and suitable for processing by scripts or - usage in generated file names. This + usage in generated filenames. This field is optional. Example: VERSION_ID=17 or VERSION_ID=11.04. @@ -213,7 +236,7 @@ presentation to the user. May or may not contain a release code name or OS version of some kind, as suitable. If - not set defaults to + not set, defaults to PRETTY_NAME="Linux". Example: PRETTY_NAME="Fedora 17 (Beefy Miracle)". @@ -241,7 +264,7 @@ A CPE name for the operating system, following the Common + url="https://cpe.mitre.org/specification/">Common Platform Enumeration Specification as proposed by the MITRE Corporation. This field @@ -290,7 +313,7 @@ tel:. Only one URL shall be listed in each setting. If multiple resources need to be - referenced it is recommended to + referenced, it is recommended to provide an online landing page linking all available resources. Examples: HOME_URL="https://fedoraproject.org/" @@ -332,7 +355,7 @@ Note that operating system vendors may choose not to provide version information, for example to - accommodate for rolling releases. In this case VERSION + accommodate for rolling releases. In this case, VERSION and VERSION_ID may be unset. Applications should not rely on these fields to be set.