Documentation / git-describe.txton commit Make read_patch_file work on a strbuf. (9a76ade)
   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
  54EXAMPLES
  55--------
  56
  57With something like git.git current tree, I get:
  58
  59        [torvalds@g5 git]$ git-describe parent
  60        v1.0.4-14-g2414721
  61
  62i.e. the current head of my "parent" branch is based on v1.0.4,
  63but since it has a handful commits on top of that,
  64describe has added the number of additional commits ("14") and
  65an abbreviated object name for the commit itself ("2414721")
  66at the end.
  67
  68The number of additional commits is the number
  69of commits which would be displayed by "git log v1.0.4..parent".
  70The hash suffix is "-g" + 7-char abbreviation for the tip commit
  71of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
  72
  73Doing a "git-describe" on a tag-name will just show the tag name:
  74
  75        [torvalds@g5 git]$ git-describe v1.0.4
  76        v1.0.4
  77
  78With --all, the command can use branch heads as references, so
  79the output shows the reference path as well:
  80
  81        [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
  82        tags/v1.0.0-21-g975b
  83
  84        [torvalds@g5 git]$ git describe --all HEAD^
  85        heads/lt/describe-7-g975b
  86
  87With --abbrev set to 0, the command can be used to find the
  88closest tagname without any suffix:
  89
  90        [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
  91        tags/v1.0.0
  92
  93SEARCH STRATEGY
  94---------------
  95
  96For each committish supplied "git describe" will first look for
  97a tag which tags exactly that commit.  Annotated tags will always
  98be preferred over lightweight tags, and tags with newer dates will
  99always be preferred over tags with older dates.  If an exact match
 100is found, its name will be output and searching will stop.
 101
 102If an exact match was not found "git describe" will walk back
 103through the commit history to locate an ancestor commit which
 104has been tagged.  The ancestor's tag will be output along with an
 105abbreviation of the input committish's SHA1.
 106
 107If multiple tags were found during the walk then the tag which
 108has the fewest commits different from the input committish will be
 109selected and output.  Here fewest commits different is defined as
 110the number of commits which would be shown by "git log tag..input"
 111will be the smallest number of commits possible.
 112
 113
 114Author
 115------
 116Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
 117butchered by Junio C Hamano <junkio@cox.net>.  Later significantly
 118updated by Shawn Pearce <spearce@spearce.org>.
 119
 120Documentation
 121--------------
 122Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 123
 124GIT
 125---
 126Part of the gitlink:git[7] suite