Documentation/git-describe.txt

   1 git-describe(1)
   2 ===============
   3
   4 NAME
   5 ----
   6 git-describe - Describe a commit using the most recent tag reachable from it
   7
   8
   9 SYNOPSIS
  10 --------
  11 [verse]
  12 'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...]
  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 <commit-ish>...::
  30         Commit-ish object names to describe.  Defaults to HEAD if omitted.
  31
  32 --dirty[=<mark>]::
  33 --broken[=<mark>]::
  34         Describe the state of the working tree.  When the working
  35         tree matches HEAD, the output is the same as "git describe
  36         HEAD".  If the working tree has local modification "-dirty"
  37         is appended to it.  If a repository is corrupt and Git
  38         cannot determine if there is local modification, Git will
  39         error out, unless `--broken' is given, which appends
  40         the suffix "-broken" instead.
  41
  42 --all::
  43         Instead of using only the annotated tags, use any ref
  44         found in `refs/` namespace.  This option enables matching
  45         any known branch, remote-tracking branch, or lightweight tag.
  46
  47 --tags::
  48         Instead of using only the annotated tags, use any tag
  49         found in `refs/tags` namespace.  This option enables matching
  50         a lightweight (non-annotated) tag.
  51
  52 --contains::
  53         Instead of finding the tag that predates the commit, find
  54         the tag that comes after the commit, and thus contains it.
  55         Automatically implies --tags.
  56
  57 --abbrev=<n>::
  58         Instead of using the default 7 hexadecimal digits as the
  59         abbreviated object name, use <n> digits, or as many digits
  60         as needed to form a unique object name.  An <n> of 0
  61         will suppress long format, only showing the closest tag.
  62
  63 --candidates=<n>::
  64         Instead of considering only the 10 most recent tags as
  65         candidates to describe the input commit-ish consider
  66         up to <n> candidates.  Increasing <n> above 10 will take
  67         slightly longer but may produce a more accurate result.
  68         An <n> of 0 will cause only exact matches to be output.
  69
  70 --exact-match::
  71         Only output exact matches (a tag directly references the
  72         supplied commit).  This is a synonym for --candidates=0.
  73
  74 --debug::
  75         Verbosely display information about the searching strategy
  76         being employed to standard error.  The tag name will still
  77         be printed to standard out.
  78
  79 --long::
  80         Always output the long format (the tag, the number of commits
  81         and the abbreviated commit name) even when it matches a tag.
  82         This is useful when you want to see parts of the commit object name
  83         in "describe" output, even when the commit in question happens to be
  84         a tagged version.  Instead of just emitting the tag name, it will
  85         describe such a commit as v1.2-0-gdeadbee (0th commit since tag v1.2
  86         that points at object deadbee....).
  87
  88 --match <pattern>::
  89         Only consider tags matching the given `glob(7)` pattern,
  90         excluding the "refs/tags/" prefix. If used with `--all`, it also
  91         considers local branches and remote-tracking references matching the
  92         pattern, excluding respectively "refs/heads/" and "refs/remotes/"
  93         prefix; references of other types are never considered. If given
  94         multiple times, a list of patterns will be accumulated, and tags
  95         matching any of the patterns will be considered.  Use `--no-match` to
  96         clear and reset the list of patterns.
  97
  98 --exclude <pattern>::
  99         Do not consider tags matching the given `glob(7)` pattern, excluding
 100         the "refs/tags/" prefix. If used with `--all`, it also does not consider
 101         local branches and remote-tracking references matching the pattern,
 102         excluding respectively "refs/heads/" and "refs/remotes/" prefix;
 103         references of other types are never considered. If given multiple times,
 104         a list of patterns will be accumulated and tags matching any of the
 105         patterns will be excluded. When combined with --match a tag will be
 106         considered when it matches at least one --match pattern and does not
 107         match any of the --exclude patterns. Use `--no-exclude` to clear and
 108         reset the list of patterns.
 109
 110 --always::
 111         Show uniquely abbreviated commit object as fallback.
 112
 113 --first-parent::
 114         Follow only the first parent commit upon seeing a merge commit.
 115         This is useful when you wish to not match tags on branches merged
 116         in the history of the target commit.
 117
 118 EXAMPLES
 119 --------
 120
 121 With something like git.git current tree, I get:
 122
 123         [torvalds@g5 git]$ git describe parent
 124         v1.0.4-14-g2414721
 125
 126 i.e. the current head of my "parent" branch is based on v1.0.4,
 127 but since it has a few commits on top of that,
 128 describe has added the number of additional commits ("14") and
 129 an abbreviated object name for the commit itself ("2414721")
 130 at the end.
 131
 132 The number of additional commits is the number
 133 of commits which would be displayed by "git log v1.0.4..parent".
 134 The hash suffix is "-g" + 7-char abbreviation for the tip commit
 135 of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
 136 The "g" prefix stands for "git" and is used to allow describing the version of
 137 a software depending on the SCM the software is managed with. This is useful
 138 in an environment where people may use different SCMs.
 139
 140 Doing a 'git describe' on a tag-name will just show the tag name:
 141
 142         [torvalds@g5 git]$ git describe v1.0.4
 143         v1.0.4
 144
 145 With --all, the command can use branch heads as references, so
 146 the output shows the reference path as well:
 147
 148         [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
 149         tags/v1.0.0-21-g975b
 150
 151         [torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
 152         heads/lt/describe-7-g975b
 153
 154 With --abbrev set to 0, the command can be used to find the
 155 closest tagname without any suffix:
 156
 157         [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 158         tags/v1.0.0
 159
 160 Note that the suffix you get if you type these commands today may be
 161 longer than what Linus saw above when he ran these commands, as your
 162 Git repository may have new commits whose object names begin with
 163 975b that did not exist back then, and "-g975b" suffix alone may not
 164 be sufficient to disambiguate these commits.
 165
 166
 167 SEARCH STRATEGY
 168 ---------------
 169
 170 For each commit-ish supplied, 'git describe' will first look for
 171 a tag which tags exactly that commit.  Annotated tags will always
 172 be preferred over lightweight tags, and tags with newer dates will
 173 always be preferred over tags with older dates.  If an exact match
 174 is found, its name will be output and searching will stop.
 175
 176 If an exact match was not found, 'git describe' will walk back
 177 through the commit history to locate an ancestor commit which
 178 has been tagged.  The ancestor's tag will be output along with an
 179 abbreviation of the input commit-ish's SHA-1. If `--first-parent` was
 180 specified then the walk will only consider the first parent of each
 181 commit.
 182
 183 If multiple tags were found during the walk then the tag which
 184 has the fewest commits different from the input commit-ish will be
 185 selected and output.  Here fewest commits different is defined as
 186 the number of commits which would be shown by `git log tag..input`
 187 will be the smallest number of commits possible.
 188
 189 GIT
 190 ---
 191 Part of the linkgit:git[1] suite