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1 git-describe(1)
2 ===============
3
4 NAME
5 ----
6 git-describe - Show the most recent tag that is reachable from a commit
7
8
9 SYNOPSIS
10 --------
11 [verse]
12 'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] <committish>...
13 'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
14
15 DESCRIPTION
16 -----------
17 The command finds the most recent tag that is reachable from a
18 commit. If the tag points to the commit, then only the tag is
19 shown. Otherwise, it suffixes the tag name with the number of
20 additional commits on top of the tagged object and the
21 abbreviated object name of the most recent commit.
22
23 By default (without --all or --tags) `git describe` only shows
24 annotated tags. For more information about creating annotated tags
25 see the -a and -s options to linkgit:git-tag[1].
26
27 OPTIONS
28 -------
29 <committish>...::
30 Committish object names to describe.
31
32 --dirty[=<mark>]::
33 Describe the working tree.
34 It means describe HEAD and appends <mark> (`-dirty` by
35 default) if the working tree is dirty.
36
37 --all::
38 Instead of using only the annotated tags, use any ref
39 found in `.git/refs/`. This option enables matching
40 any known branch, remote branch, or lightweight tag.
41
42 --tags::
43 Instead of using only the annotated tags, use any tag
44 found in `.git/refs/tags`. This option enables matching
45 a lightweight (non-annotated) tag.
46
47 --contains::
48 Instead of finding the tag that predates the commit, find
49 the tag that comes after the commit, and thus contains it.
50 Automatically implies --tags.
51
52 --abbrev=<n>::
53 Instead of using the default 7 hexadecimal digits as the
54 abbreviated object name, use <n> digits, or as many digits
55 as needed to form a unique object name. An <n> of 0
56 will suppress long format, only showing the closest tag.
57
58 --candidates=<n>::
59 Instead of considering only the 10 most recent tags as
60 candidates to describe the input committish consider
61 up to <n> candidates. Increasing <n> above 10 will take
62 slightly longer but may produce a more accurate result.
63 An <n> of 0 will cause only exact matches to be output.
64
65 --exact-match::
66 Only output exact matches (a tag directly references the
67 supplied commit). This is a synonym for --candidates=0.
68
69 --debug::
70 Verbosely display information about the searching strategy
71 being employed to standard error. The tag name will still
72 be printed to standard out.
73
74 --long::
75 Always output the long format (the tag, the number of commits
76 and the abbreviated commit name) even when it matches a tag.
77 This is useful when you want to see parts of the commit object name
78 in "describe" output, even when the commit in question happens to be
79 a tagged version. Instead of just emitting the tag name, it will
80 describe such a commit as v1.2-0-gdeadbee (0th commit since tag v1.2
81 that points at object deadbee....).
82
83 --match <pattern>::
84 Only consider tags matching the given pattern (can be used to avoid
85 leaking private tags made from the repository).
86
87 --always::
88 Show uniquely abbreviated commit object as fallback.
89
90 EXAMPLES
91 --------
92
93 With something like git.git current tree, I get:
94
95 [torvalds@g5 git]$ git describe parent
96 v1.0.4-14-g2414721
97
98 i.e. the current head of my "parent" branch is based on v1.0.4,
99 but since it has a few commits on top of that,
100 describe has added the number of additional commits ("14") and
101 an abbreviated object name for the commit itself ("2414721")
102 at the end.
103
104 The number of additional commits is the number
105 of commits which would be displayed by "git log v1.0.4..parent".
106 The hash suffix is "-g" + 7-char abbreviation for the tip commit
107 of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
108
109 Doing a 'git describe' on a tag-name will just show the tag name:
110
111 [torvalds@g5 git]$ git describe v1.0.4
112 v1.0.4
113
114 With --all, the command can use branch heads as references, so
115 the output shows the reference path as well:
116
117 [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
118 tags/v1.0.0-21-g975b
119
120 [torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
121 heads/lt/describe-7-g975b
122
123 With --abbrev set to 0, the command can be used to find the
124 closest tagname without any suffix:
125
126 [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
127 tags/v1.0.0
128
129 Note that the suffix you get if you type these commands today may be
130 longer than what Linus saw above when he ran these commands, as your
131 git repository may have new commits whose object names begin with
132 975b that did not exist back then, and "-g975b" suffix alone may not
133 be sufficient to disambiguate these commits.
134
135
136 SEARCH STRATEGY
137 ---------------
138
139 For each committish supplied, 'git describe' will first look for
140 a tag which tags exactly that commit. Annotated tags will always
141 be preferred over lightweight tags, and tags with newer dates will
142 always be preferred over tags with older dates. If an exact match
143 is found, its name will be output and searching will stop.
144
145 If an exact match was not found, 'git describe' will walk back
146 through the commit history to locate an ancestor commit which
147 has been tagged. The ancestor's tag will be output along with an
148 abbreviation of the input committish's SHA1.
149
150 If multiple tags were found during the walk then the tag which
151 has the fewest commits different from the input committish will be
152 selected and output. Here fewest commits different is defined as
153 the number of commits which would be shown by `git log tag..input`
154 will be the smallest number of commits possible.
155
156
157 Author
158 ------
159 Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
160 butchered by Junio C Hamano <gitster@pobox.com>. Later significantly
161 updated by Shawn Pearce <spearce@spearce.org>.
162
163 Documentation
164 --------------
165 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
166
167 GIT
168 ---
169 Part of the linkgit:git[1] suite