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[git/git.git] / Documentation / git-describe.txt
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1git-describe(1)
2===============
3
4NAME
5----
7bd7f280 6git-describe - Show the most recent tag that is reachable from a commit
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7
8
9SYNOPSIS
10--------
23615708 11'git-describe' [--all] [--tags] [--contains] [--abbrev=<n>] <committish>...
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12
13DESCRIPTION
14-----------
15The command finds the most recent tag that is reachable from a
16commit, and if the commit itself is pointed at by the tag, shows
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17the tag. Otherwise, it suffixes the tag name with the number of
18additional commits and the abbreviated object name of the commit.
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19
20
21OPTIONS
22-------
23<committish>::
37425065 24 The object name of the committish.
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25
26--all::
27 Instead of using only the annotated tags, use any ref
28 found in `.git/refs/`.
29
30--tags::
31 Instead of using only the annotated tags, use any tag
32 found in `.git/refs/tags`.
33
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34--contains::
35 Instead of finding the tag that predates the commit, find
36 the tag that comes after the commit, and thus contains it.
37 Automatically implies --tags.
38
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39--abbrev=<n>::
40 Instead of using the default 8 hexadecimal digits as the
41 abbreviated object name, use <n> digits.
42
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43--candidates=<n>::
44 Instead of considering only the 10 most recent tags as
45 candidates to describe the input committish consider
46 up to <n> candidates. Increasing <n> above 10 will take
47 slightly longer but may produce a more accurate result.
48
49--debug::
50 Verbosely display information about the searching strategy
51 being employed to standard error. The tag name will still
52 be printed to standard out.
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53
54EXAMPLES
55--------
56
57With something like git.git current tree, I get:
58
59 [torvalds@g5 git]$ git-describe parent
1891261e 60 v1.0.4-14-g2414721
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61
62i.e. the current head of my "parent" branch is based on v1.0.4,
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63but since it has a handful commits on top of that,
64describe has added the number of additional commits ("14") and
65an abbreviated object name for the commit itself ("2414721")
66at the end.
67
68The number of additional commits is the number
69of commits which would be displayed by "git log v1.0.4..parent".
70The hash suffix is "-g" + 7-char abbreviation for the tip commit
71of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
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72
73Doing a "git-describe" on a tag-name will just show the tag name:
74
75 [torvalds@g5 git]$ git-describe v1.0.4
76 v1.0.4
77
78With --all, the command can use branch heads as references, so
79the output shows the reference path as well:
80
81 [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
1891261e 82 tags/v1.0.0-21-g975b
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83
84 [torvalds@g5 git]$ git describe --all HEAD^
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85 heads/lt/describe-7-g975b
86
87With --abbrev set to 0, the command can be used to find the
88closest tagname without any suffix:
89
90 [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
91 tags/v1.0.0
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93SEARCH STRATEGY
94---------------
95
96For each committish supplied "git describe" will first look for
97a tag which tags exactly that commit. Annotated tags will always
98be preferred over lightweight tags, and tags with newer dates will
99always be preferred over tags with older dates. If an exact match
100is found, its name will be output and searching will stop.
101
102If an exact match was not found "git describe" will walk back
103through the commit history to locate an ancestor commit which
104has been tagged. The ancestor's tag will be output along with an
105abbreviation of the input committish's SHA1.
106
107If multiple tags were found during the walk then the tag which
108has the fewest commits different from the input committish will be
109selected and output. Here fewest commits different is defined as
110the number of commits which would be shown by "git log tag..input"
111will be the smallest number of commits possible.
112
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113
114Author
115------
116Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
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117butchered by Junio C Hamano <junkio@cox.net>. Later significantly
118updated by Shawn Pearce <spearce@spearce.org>.
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119
120Documentation
121--------------
122Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
123
124GIT
125---
126Part of the gitlink:git[7] suite