1OS-RELEASE(5) os-release OS-RELEASE(5)
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3
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6 os-release, initrd-release - Operating system identification
7
9 /etc/os-release
10
11 /usr/lib/os-release
12
13 /etc/initrd-release
14
16 The /etc/os-release and /usr/lib/os-release files contain operating
17 system identification data.
18
19 The basic file format of os-release is a newline-separated list of
20 environment-like shell-compatible variable assignments. It is possible
21 to source the configuration from shell scripts, however, beyond mere
22 variable assignments, no shell features are supported (this means
23 variable expansion is explicitly not supported), allowing applications
24 to read the file without implementing a shell compatible execution
25 engine. Variable assignment values must be enclosed in double or single
26 quotes if they include spaces, semicolons or other special characters
27 outside of A–Z, a–z, 0–9. Shell special characters ("$", quotes,
28 backslash, backtick) must be escaped with backslashes, following shell
29 style. All strings should be in UTF-8 format, and non-printable
30 characters should not be used. It is not supported to concatenate
31 multiple individually quoted strings. Lines beginning with "#" shall be
32 ignored as comments. Blank lines are permitted and ignored.
33
34 The file /etc/os-release takes precedence over /usr/lib/os-release.
35 Applications should check for the former, and exclusively use its data
36 if it exists, and only fall back to /usr/lib/os-release if it is
37 missing. Applications should not read data from both files at the same
38 time. /usr/lib/os-release is the recommended place to store OS release
39 information as part of vendor trees. /etc/os-release should be a
40 relative symlink to /usr/lib/os-release, to provide compatibility with
41 applications only looking at /etc/. A relative symlink instead of an
42 absolute symlink is necessary to avoid breaking the link in a chroot or
43 initrd environment such as dracut.
44
45 os-release contains data that is defined by the operating system vendor
46 and should generally not be changed by the administrator.
47
48 As this file only encodes names and identifiers it should not be
49 localized.
50
51 The /etc/os-release and /usr/lib/os-release files might be symlinks to
52 other files, but it is important that the file is available from
53 earliest boot on, and hence must be located on the root file system.
54
55 For a longer rationale for os-release please refer to the Announcement
56 of /etc/os-release[1].
57
58 /etc/initrd-release
59 In the initrd[2], /etc/initrd-release plays the same role as os-release
60 in the main system. Additionally, the presence of that file means that
61 the system is in the initrd phase. /etc/os-release should be symlinked
62 to /etc/initrd-release (or vice versa), so programs that only look for
63 /etc/os-release (as described above) work correctly. The rest of this
64 document that talks about os-release should be understood to apply to
65 initrd-release too.
66
68 The following OS identifications parameters may be set using
69 os-release:
70
71 General information identifying the operating system
72 NAME=
73 A string identifying the operating system, without a version
74 component, and suitable for presentation to the user. If not set, a
75 default of "NAME=Linux" may be used.
76
77 Examples: "NAME=Fedora", "NAME="Debian GNU/Linux"".
78
79 ID=
80 A lower-case string (no spaces or other characters outside of 0–9,
81 a–z, ".", "_" and "-") identifying the operating system, excluding
82 any version information and suitable for processing by scripts or
83 usage in generated filenames. If not set, a default of "ID=linux"
84 may be used.
85
86 Examples: "ID=fedora", "ID=debian".
87
88 ID_LIKE=
89 A space-separated list of operating system identifiers in the same
90 syntax as the ID= setting. It should list identifiers of operating
91 systems that are closely related to the local operating system in
92 regards to packaging and programming interfaces, for example
93 listing one or more OS identifiers the local OS is a derivative
94 from. An OS should generally only list other OS identifiers it
95 itself is a derivative of, and not any OSes that are derived from
96 it, though symmetric relationships are possible. Build scripts and
97 similar should check this variable if they need to identify the
98 local operating system and the value of ID= is not recognized.
99 Operating systems should be listed in order of how closely the
100 local operating system relates to the listed ones, starting with
101 the closest. This field is optional.
102
103 Examples: for an operating system with "ID=centos", an assignment
104 of "ID_LIKE="rhel fedora"" would be appropriate. For an operating
105 system with "ID=ubuntu", an assignment of "ID_LIKE=debian" is
106 appropriate.
107
108 PRETTY_NAME=
109 A pretty operating system name in a format suitable for
110 presentation to the user. May or may not contain a release code
111 name or OS version of some kind, as suitable. If not set, a default
112 of "PRETTY_NAME="Linux"" may be used
113
114 Example: "PRETTY_NAME="Fedora 17 (Beefy Miracle)"".
115
116 CPE_NAME=
117 A CPE name for the operating system, in URI binding syntax,
118 following the Common Platform Enumeration Specification[3] as
119 proposed by the NIST. This field is optional.
120
121 Example: "CPE_NAME="cpe:/o:fedoraproject:fedora:17""
122
123 VARIANT=
124 A string identifying a specific variant or edition of the operating
125 system suitable for presentation to the user. This field may be
126 used to inform the user that the configuration of this system is
127 subject to a specific divergent set of rules or default
128 configuration settings. This field is optional and may not be
129 implemented on all systems.
130
131 Examples: "VARIANT="Server Edition"", "VARIANT="Smart Refrigerator
132 Edition"".
133
134 Note: this field is for display purposes only. The VARIANT_ID field
135 should be used for making programmatic decisions.
136
137 VARIANT_ID=
138 A lower-case string (no spaces or other characters outside of 0–9,
139 a–z, ".", "_" and "-"), identifying a specific variant or edition
140 of the operating system. This may be interpreted by other packages
141 in order to determine a divergent default configuration. This field
142 is optional and may not be implemented on all systems.
143
144 Examples: "VARIANT_ID=server", "VARIANT_ID=embedded".
145
146 Information about the version of the operating system
147 VERSION=
148 A string identifying the operating system version, excluding any OS
149 name information, possibly including a release code name, and
150 suitable for presentation to the user. This field is optional.
151
152 Examples: "VERSION=17", "VERSION="17 (Beefy Miracle)"".
153
154 VERSION_ID=
155 A lower-case string (mostly numeric, no spaces or other characters
156 outside of 0–9, a–z, ".", "_" and "-") identifying the operating
157 system version, excluding any OS name information or release code
158 name, and suitable for processing by scripts or usage in generated
159 filenames. This field is optional.
160
161 Examples: "VERSION_ID=17", "VERSION_ID=11.04".
162
163 VERSION_CODENAME=
164 A lower-case string (no spaces or other characters outside of 0–9,
165 a–z, ".", "_" and "-") identifying the operating system release
166 code name, excluding any OS name information or release version,
167 and suitable for processing by scripts or usage in generated
168 filenames. This field is optional and may not be implemented on all
169 systems.
170
171 Examples: "VERSION_CODENAME=buster", "VERSION_CODENAME=xenial".
172
173 BUILD_ID=
174 A string uniquely identifying the system image originally used as
175 the installation base. In most cases, VERSION_ID or
176 IMAGE_ID+IMAGE_VERSION are updated when the entire system image is
177 replaced during an update. BUILD_ID may be used in distributions
178 where the original installation image version is important:
179 VERSION_ID would change during incremental system updates, but
180 BUILD_ID would not. This field is optional.
181
182 Examples: "BUILD_ID="2013-03-20.3"", "BUILD_ID=201303203".
183
184 IMAGE_ID=
185 A lower-case string (no spaces or other characters outside of 0–9,
186 a–z, ".", "_" and "-"), identifying a specific image of the
187 operating system. This is supposed to be used for environments
188 where OS images are prepared, built, shipped and updated as
189 comprehensive, consistent OS images. This field is optional and may
190 not be implemented on all systems, in particularly not on those
191 that are not managed via images but put together and updated from
192 individual packages and on the local system.
193
194 Examples: "IMAGE_ID=vendorx-cashier-system",
195 "IMAGE_ID=netbook-image".
196
197 IMAGE_VERSION=
198 A lower-case string (mostly numeric, no spaces or other characters
199 outside of 0–9, a–z, ".", "_" and "-") identifying the OS image
200 version. This is supposed to be used together with IMAGE_ID
201 described above, to discern different versions of the same image.
202
203 Examples: "IMAGE_VERSION=33", "IMAGE_VERSION=47.1rc1".
204
205 To summarize: if the image updates are built and shipped as
206 comprehensive units, IMAGE_ID+IMAGE_VERSION is the best fit. Otherwise,
207 if updates eventually completely replace previously installed contents,
208 as in a typical binary distribution, VERSION_ID should be used to
209 identify major releases of the operating system. BUILD_ID may be used
210 instead or in addition to VERSION_ID when the original system image
211 version is important.
212
213 Presentation information and links
214 HOME_URL=, DOCUMENTATION_URL=, SUPPORT_URL=, BUG_REPORT_URL=,
215 PRIVACY_POLICY_URL=
216 Links to resources on the Internet related to the operating system.
217 HOME_URL= should refer to the homepage of the operating system, or
218 alternatively some homepage of the specific version of the
219 operating system. DOCUMENTATION_URL= should refer to the main
220 documentation page for this operating system. SUPPORT_URL= should
221 refer to the main support page for the operating system, if there
222 is any. This is primarily intended for operating systems which
223 vendors provide support for. BUG_REPORT_URL= should refer to the
224 main bug reporting page for the operating system, if there is any.
225 This is primarily intended for operating systems that rely on
226 community QA. PRIVACY_POLICY_URL= should refer to the main privacy
227 policy page for the operating system, if there is any. These
228 settings are optional, and providing only some of these settings is
229 common. These URLs are intended to be exposed in "About this
230 system" UIs behind links with captions such as "About this
231 Operating System", "Obtain Support", "Report a Bug", or "Privacy
232 Policy". The values should be in RFC3986 format[4], and should be
233 "http:" or "https:" URLs, and possibly "mailto:" or "tel:". Only
234 one URL shall be listed in each setting. If multiple resources need
235 to be referenced, it is recommended to provide an online landing
236 page linking all available resources.
237
238 Examples: "HOME_URL="https://fedoraproject.org/"",
239 "BUG_REPORT_URL="https://bugzilla.redhat.com/"".
240
241 LOGO=
242 A string, specifying the name of an icon as defined by
243 freedesktop.org Icon Theme Specification[5]. This can be used by
244 graphical applications to display an operating system's or
245 distributor's logo. This field is optional and may not necessarily
246 be implemented on all systems.
247
248 Examples: "LOGO=fedora-logo", "LOGO=distributor-logo-opensuse"
249
250 ANSI_COLOR=
251 A suggested presentation color when showing the OS name on the
252 console. This should be specified as string suitable for inclusion
253 in the ESC [ m ANSI/ECMA-48 escape code for setting graphical
254 rendition. This field is optional.
255
256 Examples: "ANSI_COLOR="0;31"" for red, "ANSI_COLOR="1;34"" for
257 light blue, or "ANSI_COLOR="0;38;2;60;110;180"" for Fedora blue.
258
259 Distribution-level defaults and metadata
260 DEFAULT_HOSTNAME=
261 A string specifying the hostname if hostname(5) is not present and
262 no other configuration source specifies the hostname. Must be
263 either a single DNS label (a string composed of 7-bit ASCII
264 lower-case characters and no spaces or dots, limited to the format
265 allowed for DNS domain name labels), or a sequence of such labels
266 separated by single dots that forms a valid DNS FQDN. The hostname
267 must be at most 64 characters, which is a Linux limitation (DNS
268 allows longer names).
269
270 See org.freedesktop.hostname1(5) for a description of how systemd-
271 hostnamed.service(8) determines the fallback hostname.
272
273 SYSEXT_LEVEL=
274 A lower-case string (mostly numeric, no spaces or other characters
275 outside of 0–9, a–z, ".", "_" and "-") identifying the operating
276 system extensions support level, to indicate which extension images
277 are supported. See systemd-sysext(8)) for more information.
278
279 Examples: "SYSEXT_LEVEL=2", "SYSEXT_LEVEL=15.14".
280
281 Notes
282 If you are using this file to determine the OS or a specific version of
283 it, use the ID and VERSION_ID fields, possibly with ID_LIKE as fallback
284 for ID. When looking for an OS identification string for presentation
285 to the user use the PRETTY_NAME field.
286
287 Note that operating system vendors may choose not to provide version
288 information, for example to accommodate for rolling releases. In this
289 case, VERSION and VERSION_ID may be unset. Applications should not rely
290 on these fields to be set.
291
292 Operating system vendors may extend the file format and introduce new
293 fields. It is highly recommended to prefix new fields with an OS
294 specific name in order to avoid name clashes. Applications reading this
295 file must ignore unknown fields.
296
297 Example: "DEBIAN_BTS="debbugs://bugs.debian.org/"".
298
299 Container and sandbox runtime managers may make the host's
300 identification data available to applications by providing the host's
301 /etc/os-release (if available, otherwise /usr/lib/os-release as a
302 fallback) as /run/host/os-release.
303
305 Example 1. os-release file for Fedora Workstation
306
307 NAME=Fedora
308 VERSION="32 (Workstation Edition)"
309 ID=fedora
310 VERSION_ID=32
311 PRETTY_NAME="Fedora 32 (Workstation Edition)"
312 ANSI_COLOR="0;38;2;60;110;180"
313 LOGO=fedora-logo-icon
314 CPE_NAME="cpe:/o:fedoraproject:fedora:32"
315 HOME_URL="https://fedoraproject.org/"
316 DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f32/system-administrators-guide/"
317 SUPPORT_URL="https://fedoraproject.org/wiki/Communicating_and_getting_help"
318 BUG_REPORT_URL="https://bugzilla.redhat.com/"
319 REDHAT_BUGZILLA_PRODUCT="Fedora"
320 REDHAT_BUGZILLA_PRODUCT_VERSION=32
321 REDHAT_SUPPORT_PRODUCT="Fedora"
322 REDHAT_SUPPORT_PRODUCT_VERSION=32
323 PRIVACY_POLICY_URL="https://fedoraproject.org/wiki/Legal:PrivacyPolicy"
324 VARIANT="Workstation Edition"
325 VARIANT_ID=workstation
326
327 Example 2. Reading os-release in sh(1)
328
329 #!/bin/sh -eu
330
331 test -e /etc/os-release && os_release='/etc/os-release' || os_release='/usr/lib/os-release'
332 . "${os_release}"
333
334 echo "Running on ${PRETTY_NAME:-Linux}"
335
336 if [ "${ID:-linux}" = "debian" ] || [ "${ID_LIKE#*debian*}" != "${ID_LIKE}" ]; then
337 echo "Looks like Debian!"
338 fi
339
340 Example 3. Reading os-release in python(1)
341
342 #!/usr/bin/python
343
344 import ast
345 import re
346 import sys
347
348 def read_os_release():
349 try:
350 filename = '/etc/os-release'
351 f = open(filename)
352 except FileNotFoundError:
353 filename = '/usr/lib/os-release'
354 f = open(filename)
355
356 for line_number, line in enumerate(f):
357 line = line.rstrip()
358 if not line or line.startswith('#'):
359 continue
360 if m := re.match(r'([A-Z][A-Z_0-9]+)=(.*)', line):
361 name, val = m.groups()
362 if val and val[0] in '"\'':
363 val = ast.literal_eval(val)
364 yield name, val
365 else:
366 print(f'{filename}:{line_number + 1}: bad line {line!r}',
367 file=sys.stderr)
368
369 os_release = dict(read_os_release())
370
371 pretty_name = os_release.get('PRETTY_NAME', 'Linux')
372 print(f'Running on {pretty_name}')
373
374 if 'debian' in [os_release.get('ID', 'linux'),
375 *os_release.get('ID_LIKE', '').split()]:
376 print('Looks like Debian!')
377
379 systemd(1), lsb_release(1), hostname(5), machine-id(5), machine-info(5)
380
382 1. Announcement of /etc/os-release
383 http://0pointer.de/blog/projects/os-release
384
385 2. initrd
386 https://www.kernel.org/doc/html/latest/admin-guide/initrd.html
387
388 3. Common Platform Enumeration Specification
389 http://scap.nist.gov/specifications/cpe/
390
391 4. RFC3986 format
392 https://tools.ietf.org/html/rfc3986
393
394 5. freedesktop.org Icon Theme Specification
395 http://standards.freedesktop.org/icon-theme-spec/latest
396
397
398
399systemd 249 OS-RELEASE(5)