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.  If the tag points to the commit, then only the tag is
  17 shown.  Otherwise, it suffixes the tag name with the number of
  18 additional commits on top of the tagged object and the
  19 abbreviated object name of the most recent commit.
  20
  21
  22 OPTIONS
  23 -------
  24 <committish>::
  25         The object name of the committish.
  26
  27 --all::
  28         Instead of using only the annotated tags, use any ref
  29         found in `.git/refs/`.
  30
  31 --tags::
  32         Instead of using only the annotated tags, use any tag
  33         found in `.git/refs/tags`.
  34
  35 --contains::
  36         Instead of finding the tag that predates the commit, find
  37         the tag that comes after the commit, and thus contains it.
  38         Automatically implies --tags.
  39
  40 --abbrev=<n>::
  41         Instead of using the default 8 hexadecimal digits as the
  42         abbreviated object name, use <n> digits.
  43
  44 --candidates=<n>::
  45         Instead of considering only the 10 most recent tags as
  46         candidates to describe the input committish consider
  47         up to <n> candidates.  Increasing <n> above 10 will take
  48         slightly longer but may produce a more accurate result.
  49         An <n> of 0 will cause only exact matches to be output.
  50
  51 --exact-match::
  52         Only output exact matches (a tag directly references the
  53         supplied commit).  This is a synonym for --candidates=0.
  54
  55 --debug::
  56         Verbosely display information about the searching strategy
  57         being employed to standard error.  The tag name will still
  58         be printed to standard out.
  59
  60 --long::
  61         Always output the long format (the tag, the number of commits
  62         and the abbreviated commit name) even when it matches a tag.
  63         This is useful when you want to see parts of the commit object name
  64         in "describe" output, even when the commit in question happens to be
  65         a tagged version.  Instead of just emitting the tag name, it will
  66         describe such a commit as v1.2-0-deadbeef (0th commit since tag v1.2
  67         that points at object deadbeef....).
  68
  69 --match <pattern>::
  70         Only consider tags matching the given pattern (can be used to avoid
  71         leaking private tags made from the repository).
  72
  73 EXAMPLES
  74 --------
  75
  76 With something like git.git current tree, I get:
  77
  78         [torvalds@g5 git]$ git-describe parent
  79         v1.0.4-14-g2414721
  80
  81 i.e. the current head of my "parent" branch is based on v1.0.4,
  82 but since it has a handful commits on top of that,
  83 describe has added the number of additional commits ("14") and
  84 an abbreviated object name for the commit itself ("2414721")
  85 at the end.
  86
  87 The number of additional commits is the number
  88 of commits which would be displayed by "git log v1.0.4..parent".
  89 The hash suffix is "-g" + 7-char abbreviation for the tip commit
  90 of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
  91
  92 Doing a "git-describe" on a tag-name will just show the tag name:
  93
  94         [torvalds@g5 git]$ git-describe v1.0.4
  95         v1.0.4
  96
  97 With --all, the command can use branch heads as references, so
  98 the output shows the reference path as well:
  99
 100         [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
 101         tags/v1.0.0-21-g975b
 102
 103         [torvalds@g5 git]$ git describe --all HEAD^
 104         heads/lt/describe-7-g975b
 105
 106 With --abbrev set to 0, the command can be used to find the
 107 closest tagname without any suffix:
 108
 109         [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 110         tags/v1.0.0
 111
 112 SEARCH STRATEGY
 113 ---------------
 114
 115 For each committish supplied "git describe" will first look for
 116 a tag which tags exactly that commit.  Annotated tags will always
 117 be preferred over lightweight tags, and tags with newer dates will
 118 always be preferred over tags with older dates.  If an exact match
 119 is found, its name will be output and searching will stop.
 120
 121 If an exact match was not found "git describe" will walk back
 122 through the commit history to locate an ancestor commit which
 123 has been tagged.  The ancestor's tag will be output along with an
 124 abbreviation of the input committish's SHA1.
 125
 126 If multiple tags were found during the walk then the tag which
 127 has the fewest commits different from the input committish will be
 128 selected and output.  Here fewest commits different is defined as
 129 the number of commits which would be shown by "git log tag..input"
 130 will be the smallest number of commits possible.
 131
 132
 133 Author
 134 ------
 135 Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
 136 butchered by Junio C Hamano <junkio@cox.net>.  Later significantly
 137 updated by Shawn Pearce <spearce@spearce.org>.
 138
 139 Documentation
 140 --------------
 141 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 142
 143 GIT
 144 ---
 145 Part of the linkgit:git[7] suite