GIT-DESCRIBE(1) Git Manual GIT-DESCRIBE(1)
NAME
git-describe - Show the most recent tag that is reachable from a commit
SYNOPSIS
git describe [--all] [--tags] [--contains] [--abbrev=<n>] <committish>...
git describe [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
DESCRIPTION
The command finds the most recent tag that is reachable from a commit. If the tag points to the commit, then
only the tag is shown. Otherwise, it suffixes the tag name with the number of additional commits on top of the
tagged object and the abbreviated object name of the most recent commit.
By default (without --all or --tags) git describe only shows annotated tags. For more information about
creating annotated tags see the -a and -s options to git-tag(1).
OPTIONS
<committish>...
Committish object names to describe.
--dirty[=<mark>]
Describe the working tree. It means describe HEAD and appends <mark> (-dirty by default) if the working
tree is dirty.
--all
Instead of using only the annotated tags, use any ref found in refs/ namespace. This option enables
matching any known branch, remote-tracking branch, or lightweight tag.
--tags
Instead of using only the annotated tags, use any tag found in refs/tags namespace. This option enables
matching a lightweight (non-annotated) tag.
--contains
Instead of finding the tag that predates the commit, find the tag that comes after the commit, and thus
contains it. Automatically implies --tags.
--abbrev=<n>
Instead of using the default 7 hexadecimal digits as the abbreviated object name, use <n> digits, or as
many digits as needed to form a unique object name. An <n> of 0 will suppress long format, only showing
the closest tag.
--candidates=<n>
Instead of considering only the 10 most recent tags as candidates to describe the input committish
consider up to <n> candidates. Increasing <n> above 10 will take slightly longer but may produce a more
accurate result. An <n> of 0 will cause only exact matches to be output.
--exact-match
Only output exact matches (a tag directly references the supplied commit). This is a synonym for
--candidates=0.
--debug
Verbosely display information about the searching strategy being employed to standard error. The tag name
will still be printed to standard out.
--long
Always output the long format (the tag, the number of commits and the abbreviated commit name) even when
EXAMPLES
With something like git.git current tree, I get:
[torvalds@g5 git]$ git describe parent
v1.0.4-14-g2414721
i.e. the current head of my "parent" branch is based on v1.0.4, but since it has a few commits on top of that,
describe has added the number of additional commits ("14") and an abbreviated object name for the commit
itself ("2414721") at the end.
The number of additional commits is the number of commits which would be displayed by "git log
v1.0.4..parent". The hash suffix is "-g" + 7-char abbreviation for the tip commit of parent (which was
2414721b194453f058079d897d13c4e377f92dc6). The "g" prefix stands for "git" and is used to allow describing the
version of a software depending on the SCM the software is managed with. This is useful in an environment
where people may use different SCMs.
Doing a git describe on a tag-name will just show the tag name:
[torvalds@g5 git]$ git describe v1.0.4
v1.0.4
With --all, the command can use branch heads as references, so the output shows the reference path as well:
[torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
tags/v1.0.0-21-g975b
[torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
heads/lt/describe-7-g975b
With --abbrev set to 0, the command can be used to find the closest tagname without any suffix:
[torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
tags/v1.0.0
Note that the suffix you get if you type these commands today may be longer than what Linus saw above when he
ran these commands, as your Git repository may have new commits whose object names begin with 975b that did
not exist back then, and "-g975b" suffix alone may not be sufficient to disambiguate these commits.
SEARCH STRATEGY
For each committish supplied, git describe will first look for a tag which tags exactly that commit. Annotated
tags will always be preferred over lightweight tags, and tags with newer dates will always be preferred over
tags with older dates. If an exact match is found, its name will be output and searching will stop.
If an exact match was not found, git describe will walk back through the commit history to locate an ancestor
commit which has been tagged. The ancestor’s tag will be output along with an abbreviation of the input
committish’s SHA-1.
If multiple tags were found during the walk then the tag which has the fewest commits different from the input
committish will be selected and output. Here fewest commits different is defined as the number of commits
which would be shown by git log tag..input will be the smallest number of commits possible.
GIT
Part of the git(1) suite
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