Documentation / git-describe.txton commit Merge branch 'mw/sendemail' (d5c5274)
   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.  If the tag points to the commit, then only the tag is
  17shown.  Otherwise, it suffixes the tag name with the number of
  18additional commits on top of the tagged object and the
  19abbreviated object name of the most recent commit.
  20
  21
  22OPTIONS
  23-------
  24<committish>...::
  25        Committish object names to describe.
  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--always::
  74        Show uniquely abbreviated commit object as fallback.
  75
  76EXAMPLES
  77--------
  78
  79With something like git.git current tree, I get:
  80
  81        [torvalds@g5 git]$ git describe parent
  82        v1.0.4-14-g2414721
  83
  84i.e. the current head of my "parent" branch is based on v1.0.4,
  85but since it has a handful commits on top of that,
  86describe has added the number of additional commits ("14") and
  87an abbreviated object name for the commit itself ("2414721")
  88at the end.
  89
  90The number of additional commits is the number
  91of commits which would be displayed by "git log v1.0.4..parent".
  92The hash suffix is "-g" + 7-char abbreviation for the tip commit
  93of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
  94
  95Doing a 'git-describe' on a tag-name will just show the tag name:
  96
  97        [torvalds@g5 git]$ git describe v1.0.4
  98        v1.0.4
  99
 100With --all, the command can use branch heads as references, so
 101the output shows the reference path as well:
 102
 103        [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
 104        tags/v1.0.0-21-g975b
 105
 106        [torvalds@g5 git]$ git describe --all HEAD^
 107        heads/lt/describe-7-g975b
 108
 109With --abbrev set to 0, the command can be used to find the
 110closest tagname without any suffix:
 111
 112        [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 113        tags/v1.0.0
 114
 115SEARCH STRATEGY
 116---------------
 117
 118For each committish supplied, 'git-describe' will first look for
 119a tag which tags exactly that commit.  Annotated tags will always
 120be preferred over lightweight tags, and tags with newer dates will
 121always be preferred over tags with older dates.  If an exact match
 122is found, its name will be output and searching will stop.
 123
 124If an exact match was not found, 'git-describe' will walk back
 125through the commit history to locate an ancestor commit which
 126has been tagged.  The ancestor's tag will be output along with an
 127abbreviation of the input committish's SHA1.
 128
 129If multiple tags were found during the walk then the tag which
 130has the fewest commits different from the input committish will be
 131selected and output.  Here fewest commits different is defined as
 132the number of commits which would be shown by `git log tag..input`
 133will be the smallest number of commits possible.
 134
 135
 136Author
 137------
 138Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
 139butchered by Junio C Hamano <gitster@pobox.com>.  Later significantly
 140updated by Shawn Pearce <spearce@spearce.org>.
 141
 142Documentation
 143--------------
 144Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 145
 146GIT
 147---
 148Part of the linkgit:git[1] suite