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 [verse]
  12 'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] <committish>...
  13 'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>]
  14
  15 DESCRIPTION
  16 -----------
  17 The command finds the most recent tag that is reachable from a
  18 commit.  If the tag points to the commit, then only the tag is
  19 shown.  Otherwise, it suffixes the tag name with the number of
  20 additional commits on top of the tagged object and the
  21 abbreviated object name of the most recent commit.
  22
  23 By default (without --all or --tags) `git describe` only shows
  24 annotated tags.  For more information about creating annotated tags
  25 see the -a and -s options to linkgit:git-tag[1].
  26
  27 OPTIONS
  28 -------
  29 <committish>...::
  30         Committish object names to describe.
  31
  32 --dirty[=<mark>]::
  33         Describe the working tree.
  34         It means describe HEAD and appends <mark> (`-dirty` by
  35         default) if the working tree is dirty.
  36
  37 --all::
  38         Instead of using only the annotated tags, use any ref
  39         found in `.git/refs/`.  This option enables matching
  40         any known branch, remote-tracking branch, or lightweight tag.
  41
  42 --tags::
  43         Instead of using only the annotated tags, use any tag
  44         found in `.git/refs/tags`.  This option enables matching
  45         a lightweight (non-annotated) tag.
  46
  47 --contains::
  48         Instead of finding the tag that predates the commit, find
  49         the tag that comes after the commit, and thus contains it.
  50         Automatically implies --tags.
  51
  52 --abbrev=<n>::
  53         Instead of using the default 7 hexadecimal digits as the
  54         abbreviated object name, use <n> digits, or as many digits
  55         as needed to form a unique object name.  An <n> of 0
  56         will suppress long format, only showing the closest tag.
  57
  58 --candidates=<n>::
  59         Instead of considering only the 10 most recent tags as
  60         candidates to describe the input committish consider
  61         up to <n> candidates.  Increasing <n> above 10 will take
  62         slightly longer but may produce a more accurate result.
  63         An <n> of 0 will cause only exact matches to be output.
  64
  65 --exact-match::
  66         Only output exact matches (a tag directly references the
  67         supplied commit).  This is a synonym for --candidates=0.
  68
  69 --debug::
  70         Verbosely display information about the searching strategy
  71         being employed to standard error.  The tag name will still
  72         be printed to standard out.
  73
  74 --long::
  75         Always output the long format (the tag, the number of commits
  76         and the abbreviated commit name) even when it matches a tag.
  77         This is useful when you want to see parts of the commit object name
  78         in "describe" output, even when the commit in question happens to be
  79         a tagged version.  Instead of just emitting the tag name, it will
  80         describe such a commit as v1.2-0-gdeadbee (0th commit since tag v1.2
  81         that points at object deadbee....).
  82
  83 --match <pattern>::
  84         Only consider tags matching the given pattern (can be used to avoid
  85         leaking private tags made from the repository).
  86
  87 --always::
  88         Show uniquely abbreviated commit object as fallback.
  89
  90 EXAMPLES
  91 --------
  92
  93 With something like git.git current tree, I get:
  94
  95         [torvalds@g5 git]$ git describe parent
  96         v1.0.4-14-g2414721
  97
  98 i.e. the current head of my "parent" branch is based on v1.0.4,
  99 but since it has a few commits on top of that,
 100 describe has added the number of additional commits ("14") and
 101 an abbreviated object name for the commit itself ("2414721")
 102 at the end.
 103
 104 The number of additional commits is the number
 105 of commits which would be displayed by "git log v1.0.4..parent".
 106 The hash suffix is "-g" + 7-char abbreviation for the tip commit
 107 of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
 108 The "g" prefix stands for "git" and is used to allow describing the version of
 109 a software depending on the SCM the software is managed with. This is useful
 110 in an environment where people may use different SCMs.
 111
 112 Doing a 'git describe' on a tag-name will just show the tag name:
 113
 114         [torvalds@g5 git]$ git describe v1.0.4
 115         v1.0.4
 116
 117 With --all, the command can use branch heads as references, so
 118 the output shows the reference path as well:
 119
 120         [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
 121         tags/v1.0.0-21-g975b
 122
 123         [torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
 124         heads/lt/describe-7-g975b
 125
 126 With --abbrev set to 0, the command can be used to find the
 127 closest tagname without any suffix:
 128
 129         [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 130         tags/v1.0.0
 131
 132 Note that the suffix you get if you type these commands today may be
 133 longer than what Linus saw above when he ran these commands, as your
 134 git repository may have new commits whose object names begin with
 135 975b that did not exist back then, and "-g975b" suffix alone may not
 136 be sufficient to disambiguate these commits.
 137
 138
 139 SEARCH STRATEGY
 140 ---------------
 141
 142 For each committish supplied, 'git describe' will first look for
 143 a tag which tags exactly that commit.  Annotated tags will always
 144 be preferred over lightweight tags, and tags with newer dates will
 145 always be preferred over tags with older dates.  If an exact match
 146 is found, its name will be output and searching will stop.
 147
 148 If an exact match was not found, 'git describe' will walk back
 149 through the commit history to locate an ancestor commit which
 150 has been tagged.  The ancestor's tag will be output along with an
 151 abbreviation of the input committish's SHA1.
 152
 153 If multiple tags were found during the walk then the tag which
 154 has the fewest commits different from the input committish will be
 155 selected and output.  Here fewest commits different is defined as
 156 the number of commits which would be shown by `git log tag..input`
 157 will be the smallest number of commits possible.
 158
 159 GIT
 160 ---
 161 Part of the linkgit:git[1] suite