1GIT-DESCRIBE(1) Git Manual GIT-DESCRIBE(1)
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6 git-describe - Give an object a human readable name based on an
7 available ref
8
10 git describe [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...]
11 git describe [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
12 git describe <blob>
13
15 The command finds the most recent tag that is reachable from a commit.
16 If the tag points to the commit, then only the tag is shown. Otherwise,
17 it suffixes the tag name with the number of additional commits on top
18 of the tagged object and the abbreviated object name of the most recent
19 commit. The result is a "human-readable" object name which can also be
20 used to identify the commit to other git commands.
21 By default (without --all or --tags) git describe only shows annotated
23 tags. For more information about creating annotated tags see the -a and
24 -s options to git-tag(1).
25 If the given object refers to a blob, it will be described as
27 <commit-ish>:<path>, such that the blob can be found at <path> in the
28 <commit-ish>, which itself describes the first commit in which this
29 blob occurs in a reverse revision walk from HEAD.
30
32 <commit-ish>...
33 Commit-ish object names to describe. Defaults to HEAD if omitted.
34 --dirty[=<mark>], --broken[=<mark>]
36 Describe the state of the working tree. When the working tree
37 matches HEAD, the output is the same as "git describe HEAD". If the
38 working tree has local modification "-dirty" is appended to it. If
39 a repository is corrupt and Git cannot determine if there is local
40 modification, Git will error out, unless “--broken” is given, which
41 appends the suffix "-broken" instead.
42 --all
44 Instead of using only the annotated tags, use any ref found in
45 refs/ namespace. This option enables matching any known branch,
46 remote-tracking branch, or lightweight tag.
47 --tags
49 Instead of using only the annotated tags, use any tag found in
50 refs/tags namespace. This option enables matching a lightweight
51 (non-annotated) tag.
52 --contains
54 Instead of finding the tag that predates the commit, find the tag
55 that comes after the commit, and thus contains it. Automatically
56 implies --tags.
57 --abbrev=<n>
59 Instead of using the default number of hexadecimal digits (which
60 will vary according to the number of objects in the repository with
61 a default of 7) of the abbreviated object name, use <n> digits, or
62 as many digits as needed to form a unique object name. An <n> of 0
63 will suppress long format, only showing the closest tag.
64 --candidates=<n>
66 Instead of considering only the 10 most recent tags as candidates
67 to describe the input commit-ish consider up to <n> candidates.
68 Increasing <n> above 10 will take slightly longer but may produce a
69 more accurate result. An <n> of 0 will cause only exact matches to
70 be output.
71 --exact-match
73 Only output exact matches (a tag directly references the supplied
74 commit). This is a synonym for --candidates=0.
75 --debug
77 Verbosely display information about the searching strategy being
78 employed to standard error. The tag name will still be printed to
79 standard out.
80 --long
82 Always output the long format (the tag, the number of commits and
83 the abbreviated commit name) even when it matches a tag. This is
84 useful when you want to see parts of the commit object name in
85 "describe" output, even when the commit in question happens to be a
86 tagged version. Instead of just emitting the tag name, it will
87 describe such a commit as v1.2-0-gdeadbee (0th commit since tag
88 v1.2 that points at object deadbee....).
89 --match <pattern>
91 Only consider tags matching the given glob(7) pattern, excluding
92 the "refs/tags/" prefix. If used with --all, it also considers
93 local branches and remote-tracking references matching the pattern,
94 excluding respectively "refs/heads/" and "refs/remotes/" prefix;
95 references of other types are never considered. If given multiple
96 times, a list of patterns will be accumulated, and tags matching
97 any of the patterns will be considered. Use --no-match to clear and
98 reset the list of patterns.
99 --exclude <pattern>
101 Do not consider tags matching the given glob(7) pattern, excluding
102 the "refs/tags/" prefix. If used with --all, it also does not
103 consider local branches and remote-tracking references matching the
104 pattern, excluding respectively "refs/heads/" and "refs/remotes/"
105 prefix; references of other types are never considered. If given
106 multiple times, a list of patterns will be accumulated and tags
107 matching any of the patterns will be excluded. When combined with
108 --match a tag will be considered when it matches at least one
109 --match pattern and does not match any of the --exclude patterns.
110 Use --no-exclude to clear and reset the list of patterns.
111 --always
113 Show uniquely abbreviated commit object as fallback.
114 --first-parent
116 Follow only the first parent commit upon seeing a merge commit.
117 This is useful when you wish to not match tags on branches merged
118 in the history of the target commit.
119
121 With something like git.git current tree, I get:
122 [torvalds@g5 git]$ git describe parent
124 v1.0.4-14-g2414721
125 i.e. the current head of my "parent" branch is based on v1.0.4, but
127 since it has a few commits on top of that, describe has added the
128 number of additional commits ("14") and an abbreviated object name for
129 the commit itself ("2414721") at the end.
130 The number of additional commits is the number of commits which would
132 be displayed by "git log v1.0.4..parent". The hash suffix is "-g" + an
133 unambigous abbreviation for the tip commit of parent (which was
134 2414721b194453f058079d897d13c4e377f92dc6). The length of the
135 abbreviation scales as the repository grows, using the approximate
136 number of objects in the repository and a bit of math around the
137 birthday paradox, and defaults to a minimum of 7. The "g" prefix stands
138 for "git" and is used to allow describing the version of a software
139 depending on the SCM the software is managed with. This is useful in an
140 environment where people may use different SCMs.
141 Doing a git describe on a tag-name will just show the tag name:
143 [torvalds@g5 git]$ git describe v1.0.4
145 v1.0.4
146 With --all, the command can use branch heads as references, so the
148 output shows the reference path as well:
149 [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
151 tags/v1.0.0-21-g975b
152 [torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
154 heads/lt/describe-7-g975b
155 With --abbrev set to 0, the command can be used to find the closest
157 tagname without any suffix:
158 [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
160 tags/v1.0.0
161 Note that the suffix you get if you type these commands today may be
163 longer than what Linus saw above when he ran these commands, as your
164 Git repository may have new commits whose object names begin with 975b
165 that did not exist back then, and "-g975b" suffix alone may not be
166 sufficient to disambiguate these commits.
167
169 For each commit-ish supplied, git describe will first look for a tag
170 which tags exactly that commit. Annotated tags will always be preferred
171 over lightweight tags, and tags with newer dates will always be
172 preferred over tags with older dates. If an exact match is found, its
173 name will be output and searching will stop.
174 If an exact match was not found, git describe will walk back through
176 the commit history to locate an ancestor commit which has been tagged.
177 The ancestor’s tag will be output along with an abbreviation of the
178 input commit-ish’s SHA-1. If --first-parent was specified then the walk
179 will only consider the first parent of each commit.
180 If multiple tags were found during the walk then the tag which has the
182 fewest commits different from the input commit-ish will be selected and
183 output. Here fewest commits different is defined as the number of
184 commits which would be shown by git log tag..input will be the smallest
185 number of commits possible.
186
188 Tree objects as well as tag objects not pointing at commits, cannot be
189 described. When describing blobs, the lightweight tags pointing at
190 blobs are ignored, but the blob is still described as
191 <committ-ish>:<path> despite the lightweight tag being favorable.
192
194 Part of the git(1) suite
195Git 2.33.1 2021-10-12 GIT-DESCRIBE(1)