Documentation / git-describe.txton commit Merge branch 'pb/prepare-commit-msg' (1ae419c)
   1git-describe(1)
   2===============
   3
   4NAME
   5----
   6git-describe - Show the most recent tag that is reachable from a commit
   7
   8
   9SYNOPSIS
  10--------
  11'git-describe' [--all] [--tags] [--contains] [--abbrev=<n>] <committish>...
  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
  17the tag.  Otherwise, it suffixes the tag name with the number of
  18additional commits and the abbreviated object name of the commit.
  19
  20
  21OPTIONS
  22-------
  23<committish>::
  24        The object name of the committish.
  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
  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
  39--abbrev=<n>::
  40        Instead of using the default 8 hexadecimal digits as the
  41        abbreviated object name, use <n> digits.
  42
  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.
  53
  54--match <pattern>::
  55        Only consider tags matching the given pattern (can be used to avoid
  56        leaking private tags made from the repository).
  57
  58EXAMPLES
  59--------
  60
  61With something like git.git current tree, I get:
  62
  63        [torvalds@g5 git]$ git-describe parent
  64        v1.0.4-14-g2414721
  65
  66i.e. the current head of my "parent" branch is based on v1.0.4,
  67but since it has a handful commits on top of that,
  68describe has added the number of additional commits ("14") and
  69an abbreviated object name for the commit itself ("2414721")
  70at the end.
  71
  72The number of additional commits is the number
  73of commits which would be displayed by "git log v1.0.4..parent".
  74The hash suffix is "-g" + 7-char abbreviation for the tip commit
  75of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
  76
  77Doing a "git-describe" on a tag-name will just show the tag name:
  78
  79        [torvalds@g5 git]$ git-describe v1.0.4
  80        v1.0.4
  81
  82With --all, the command can use branch heads as references, so
  83the output shows the reference path as well:
  84
  85        [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
  86        tags/v1.0.0-21-g975b
  87
  88        [torvalds@g5 git]$ git describe --all HEAD^
  89        heads/lt/describe-7-g975b
  90
  91With --abbrev set to 0, the command can be used to find the
  92closest tagname without any suffix:
  93
  94        [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
  95        tags/v1.0.0
  96
  97SEARCH STRATEGY
  98---------------
  99
 100For each committish supplied "git describe" will first look for
 101a tag which tags exactly that commit.  Annotated tags will always
 102be preferred over lightweight tags, and tags with newer dates will
 103always be preferred over tags with older dates.  If an exact match
 104is found, its name will be output and searching will stop.
 105
 106If an exact match was not found "git describe" will walk back
 107through the commit history to locate an ancestor commit which
 108has been tagged.  The ancestor's tag will be output along with an
 109abbreviation of the input committish's SHA1.
 110
 111If multiple tags were found during the walk then the tag which
 112has the fewest commits different from the input committish will be
 113selected and output.  Here fewest commits different is defined as
 114the number of commits which would be shown by "git log tag..input"
 115will be the smallest number of commits possible.
 116
 117
 118Author
 119------
 120Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
 121butchered by Junio C Hamano <junkio@cox.net>.  Later significantly
 122updated by Shawn Pearce <spearce@spearce.org>.
 123
 124Documentation
 125--------------
 126Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 127
 128GIT
 129---
 130Part of the linkgit:git[7] suite