Documentation / git-describe.txton commit Merge branch 'tr/describe-advice' (38d3d92)
   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'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
  13
  14DESCRIPTION
  15-----------
  16The command finds the most recent tag that is reachable from a
  17commit.  If the tag points to the commit, then only the tag is
  18shown.  Otherwise, it suffixes the tag name with the number of
  19additional commits on top of the tagged object and the
  20abbreviated object name of the most recent commit.
  21
  22By default (without --all or --tags) `git describe` only shows
  23annotated tags.  For more information about creating annotated tags
  24see the -a and -s options to linkgit:git-tag[1].
  25
  26OPTIONS
  27-------
  28<committish>...::
  29        Committish object names to describe.
  30
  31--dirty[=<mark>]::
  32        Describe the working tree.
  33        It means describe HEAD and appends <mark> (`-dirty` by
  34        default) if the working tree is dirty.
  35
  36--all::
  37        Instead of using only the annotated tags, use any ref
  38        found in `.git/refs/`.  This option enables matching
  39        any known branch, remote branch, or lightweight tag.
  40
  41--tags::
  42        Instead of using only the annotated tags, use any tag
  43        found in `.git/refs/tags`.  This option enables matching
  44        a lightweight (non-annotated) tag.
  45
  46--contains::
  47        Instead of finding the tag that predates the commit, find
  48        the tag that comes after the commit, and thus contains it.
  49        Automatically implies --tags.
  50
  51--abbrev=<n>::
  52        Instead of using the default 7 hexadecimal digits as the
  53        abbreviated object name, use <n> digits, or as many digits
  54        as needed to form a unique object name.  An <n> of 0
  55        will suppress long format, only showing the closest tag.
  56
  57--candidates=<n>::
  58        Instead of considering only the 10 most recent tags as
  59        candidates to describe the input committish consider
  60        up to <n> candidates.  Increasing <n> above 10 will take
  61        slightly longer but may produce a more accurate result.
  62        An <n> of 0 will cause only exact matches to be output.
  63
  64--exact-match::
  65        Only output exact matches (a tag directly references the
  66        supplied commit).  This is a synonym for --candidates=0.
  67
  68--debug::
  69        Verbosely display information about the searching strategy
  70        being employed to standard error.  The tag name will still
  71        be printed to standard out.
  72
  73--long::
  74        Always output the long format (the tag, the number of commits
  75        and the abbreviated commit name) even when it matches a tag.
  76        This is useful when you want to see parts of the commit object name
  77        in "describe" output, even when the commit in question happens to be
  78        a tagged version.  Instead of just emitting the tag name, it will
  79        describe such a commit as v1.2-0-gdeadbee (0th commit since tag v1.2
  80        that points at object deadbee....).
  81
  82--match <pattern>::
  83        Only consider tags matching the given pattern (can be used to avoid
  84        leaking private tags made from the repository).
  85
  86--always::
  87        Show uniquely abbreviated commit object as fallback.
  88
  89EXAMPLES
  90--------
  91
  92With something like git.git current tree, I get:
  93
  94        [torvalds@g5 git]$ git describe parent
  95        v1.0.4-14-g2414721
  96
  97i.e. the current head of my "parent" branch is based on v1.0.4,
  98but since it has a few commits on top of that,
  99describe has added the number of additional commits ("14") and
 100an abbreviated object name for the commit itself ("2414721")
 101at the end.
 102
 103The number of additional commits is the number
 104of commits which would be displayed by "git log v1.0.4..parent".
 105The hash suffix is "-g" + 7-char abbreviation for the tip commit
 106of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
 107
 108Doing a 'git-describe' on a tag-name will just show the tag name:
 109
 110        [torvalds@g5 git]$ git describe v1.0.4
 111        v1.0.4
 112
 113With --all, the command can use branch heads as references, so
 114the output shows the reference path as well:
 115
 116        [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
 117        tags/v1.0.0-21-g975b
 118
 119        [torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
 120        heads/lt/describe-7-g975b
 121
 122With --abbrev set to 0, the command can be used to find the
 123closest tagname without any suffix:
 124
 125        [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 126        tags/v1.0.0
 127
 128Note that the suffix you get if you type these commands today may be
 129longer than what Linus saw above when he ran these commands, as your
 130git repository may have new commits whose object names begin with
 131975b that did not exist back then, and "-g975b" suffix alone may not
 132be sufficient to disambiguate these commits.
 133
 134
 135SEARCH STRATEGY
 136---------------
 137
 138For each committish supplied, 'git-describe' will first look for
 139a tag which tags exactly that commit.  Annotated tags will always
 140be preferred over lightweight tags, and tags with newer dates will
 141always be preferred over tags with older dates.  If an exact match
 142is found, its name will be output and searching will stop.
 143
 144If an exact match was not found, 'git-describe' will walk back
 145through the commit history to locate an ancestor commit which
 146has been tagged.  The ancestor's tag will be output along with an
 147abbreviation of the input committish's SHA1.
 148
 149If multiple tags were found during the walk then the tag which
 150has the fewest commits different from the input committish will be
 151selected and output.  Here fewest commits different is defined as
 152the number of commits which would be shown by `git log tag..input`
 153will be the smallest number of commits possible.
 154
 155
 156Author
 157------
 158Written by Linus Torvalds <torvalds@osdl.org>, but somewhat
 159butchered by Junio C Hamano <gitster@pobox.com>.  Later significantly
 160updated by Shawn Pearce <spearce@spearce.org>.
 161
 162Documentation
 163--------------
 164Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 165
 166GIT
 167---
 168Part of the linkgit:git[1] suite