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
  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 --long::
  55         Always output the long format (the tag, the number of commits
  56         and the abbreviated commit name) even when it matches a tag.
  57         This is useful when you want to see parts of the commit object name
  58         in "describe" output, even when the commit in question happens to be
  59         a tagged version.  Instead of just emitting the tag name, it will
  60         describe such a commit as v1.2-0-deadbeef (0th commit since tag v1.2
  61         that points at object deadbeef....).
  62
  63 --match <pattern>::
  64         Only consider tags matching the given pattern (can be used to avoid
  65         leaking private tags made from the repository).
  66
  67 EXAMPLES
  68 --------
  69
  70 With something like git.git current tree, I get:
  71
  72         [torvalds@g5 git]$ git-describe parent
  73         v1.0.4-14-g2414721
  74
  75 i.e. the current head of my "parent" branch is based on v1.0.4,
  76 but since it has a handful commits on top of that,
  77 describe has added the number of additional commits ("14") and
  78 an abbreviated object name for the commit itself ("2414721")
  79 at the end.
  80
  81 The number of additional commits is the number
  82 of commits which would be displayed by "git log v1.0.4..parent".
  83 The hash suffix is "-g" + 7-char abbreviation for the tip commit
  84 of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
  85
  86 Doing a "git-describe" on a tag-name will just show the tag name:
  87
  88         [torvalds@g5 git]$ git-describe v1.0.4
  89         v1.0.4
  90
  91 With --all, the command can use branch heads as references, so
  92 the output shows the reference path as well:
  93
  94         [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
  95         tags/v1.0.0-21-g975b
  96
  97         [torvalds@g5 git]$ git describe --all HEAD^
  98         heads/lt/describe-7-g975b
  99
 100 With --abbrev set to 0, the command can be used to find the
 101 closest tagname without any suffix:
 102
 103         [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 104         tags/v1.0.0
 105
 106 SEARCH STRATEGY
 107 ---------------
 108
 109 For each committish supplied "git describe" will first look for
 110 a tag which tags exactly that commit.  Annotated tags will always
 111 be preferred over lightweight tags, and tags with newer dates will
 112 always be preferred over tags with older dates.  If an exact match
 113 is found, its name will be output and searching will stop.
 114
 115 If an exact match was not found "git describe" will walk back
 116 through the commit history to locate an ancestor commit which
 117 has been tagged.  The ancestor's tag will be output along with an
 118 abbreviation of the input committish's SHA1.
 119
 120 If multiple tags were found during the walk then the tag which
 121 has the fewest commits different from the input committish will be
 122 selected and output.  Here fewest commits different is defined as
 123 the number of commits which would be shown by "git log tag..input"
 124 will be the smallest number of commits possible.
 125
 126
 127 Author
 128 ------
 129 Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
 130 butchered by Junio C Hamano <junkio@cox.net>.  Later significantly
 131 updated by Shawn Pearce <spearce@spearce.org>.
 132
 133 Documentation
 134 --------------
 135 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 136
 137 GIT
 138 ---
 139 Part of the linkgit:git[7] suite