Documentation/git-describe.txt

   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 'git-describe' [--all] [--tags] [--contains] [--abbrev=<n>] <committish>...
  12
  13 DESCRIPTION
  14 -----------
  15 The command finds the most recent tag that is reachable from a
  16 commit, and if the commit itself is pointed at by the tag, shows
  17 the tag.  Otherwise, it suffixes the tag name with the number of
  18 additional commits and the abbreviated object name of the commit.
  19
  20
  21 OPTIONS
  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         An <n> of 0 will cause only exact matches to be output.
  49
  50 --exact-match::
  51         Only output exact matches (a tag directly references the
  52         supplied commit).  This is a synonym for --candidates=0.
  53
  54 --debug::
  55         Verbosely display information about the searching strategy
  56         being employed to standard error.  The tag name will still
  57         be printed to standard out.
  58
  59 --match <pattern>::
  60         Only consider tags matching the given pattern (can be used to avoid
  61         leaking private tags made from the repository).
  62
  63 EXAMPLES
  64 --------
  65
  66 With something like git.git current tree, I get:
  67
  68         [torvalds@g5 git]$ git-describe parent
  69         v1.0.4-14-g2414721
  70
  71 i.e. the current head of my "parent" branch is based on v1.0.4,
  72 but since it has a handful commits on top of that,
  73 describe has added the number of additional commits ("14") and
  74 an abbreviated object name for the commit itself ("2414721")
  75 at the end.
  76
  77 The number of additional commits is the number
  78 of commits which would be displayed by "git log v1.0.4..parent".
  79 The hash suffix is "-g" + 7-char abbreviation for the tip commit
  80 of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
  81
  82 Doing a "git-describe" on a tag-name will just show the tag name:
  83
  84         [torvalds@g5 git]$ git-describe v1.0.4
  85         v1.0.4
  86
  87 With --all, the command can use branch heads as references, so
  88 the output shows the reference path as well:
  89
  90         [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
  91         tags/v1.0.0-21-g975b
  92
  93         [torvalds@g5 git]$ git describe --all HEAD^
  94         heads/lt/describe-7-g975b
  95
  96 With --abbrev set to 0, the command can be used to find the
  97 closest tagname without any suffix:
  98
  99         [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 100         tags/v1.0.0
 101
 102 SEARCH STRATEGY
 103 ---------------
 104
 105 For each committish supplied "git describe" will first look for
 106 a tag which tags exactly that commit.  Annotated tags will always
 107 be preferred over lightweight tags, and tags with newer dates will
 108 always be preferred over tags with older dates.  If an exact match
 109 is found, its name will be output and searching will stop.
 110
 111 If an exact match was not found "git describe" will walk back
 112 through the commit history to locate an ancestor commit which
 113 has been tagged.  The ancestor's tag will be output along with an
 114 abbreviation of the input committish's SHA1.
 115
 116 If multiple tags were found during the walk then the tag which
 117 has the fewest commits different from the input committish will be
 118 selected and output.  Here fewest commits different is defined as
 119 the number of commits which would be shown by "git log tag..input"
 120 will be the smallest number of commits possible.
 121
 122
 123 Author
 124 ------
 125 Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
 126 butchered by Junio C Hamano <junkio@cox.net>.  Later significantly
 127 updated by Shawn Pearce <spearce@spearce.org>.
 128
 129 Documentation
 130 --------------
 131 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 132
 133 GIT
 134 ---
 135 Part of the linkgit:git[7] suite