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.  This can be used to avoid
  91         leaking private tags from the repository. If given multiple times, a
  92         list of patterns will be accumulated, and tags matching any of the
  93         patterns will be considered. Use `--no-match` to clear and reset the
  94         list of patterns.
  95
  96 --exclude <pattern>::
  97         Do not consider tags matching the given `glob(7)` pattern, excluding
  98         the "refs/tags/" prefix. This can be used to narrow the tag space and
  99         find only tags matching some meaningful criteria. If given multiple
 100         times, a list of patterns will be accumulated and tags matching any
 101         of the patterns will be excluded. When combined with --match a tag will
 102         be considered when it matches at least one --match pattern and does not
 103         match any of the --exclude patterns. Use `--no-exclude` to clear and
 104         reset the list of patterns.
 105
 106 --always::
 107         Show uniquely abbreviated commit object as fallback.
 108
 109 --first-parent::
 110         Follow only the first parent commit upon seeing a merge commit.
 111         This is useful when you wish to not match tags on branches merged
 112         in the history of the target commit.
 113
 114 EXAMPLES
 115 --------
 116
 117 With something like git.git current tree, I get:
 118
 119         [torvalds@g5 git]$ git describe parent
 120         v1.0.4-14-g2414721
 121
 122 i.e. the current head of my "parent" branch is based on v1.0.4,
 123 but since it has a few commits on top of that,
 124 describe has added the number of additional commits ("14") and
 125 an abbreviated object name for the commit itself ("2414721")
 126 at the end.
 127
 128 The number of additional commits is the number
 129 of commits which would be displayed by "git log v1.0.4..parent".
 130 The hash suffix is "-g" + 7-char abbreviation for the tip commit
 131 of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
 132 The "g" prefix stands for "git" and is used to allow describing the version of
 133 a software depending on the SCM the software is managed with. This is useful
 134 in an environment where people may use different SCMs.
 135
 136 Doing a 'git describe' on a tag-name will just show the tag name:
 137
 138         [torvalds@g5 git]$ git describe v1.0.4
 139         v1.0.4
 140
 141 With --all, the command can use branch heads as references, so
 142 the output shows the reference path as well:
 143
 144         [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2
 145         tags/v1.0.0-21-g975b
 146
 147         [torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^
 148         heads/lt/describe-7-g975b
 149
 150 With --abbrev set to 0, the command can be used to find the
 151 closest tagname without any suffix:
 152
 153         [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2
 154         tags/v1.0.0
 155
 156 Note that the suffix you get if you type these commands today may be
 157 longer than what Linus saw above when he ran these commands, as your
 158 Git repository may have new commits whose object names begin with
 159 975b that did not exist back then, and "-g975b" suffix alone may not
 160 be sufficient to disambiguate these commits.
 161
 162
 163 SEARCH STRATEGY
 164 ---------------
 165
 166 For each commit-ish supplied, 'git describe' will first look for
 167 a tag which tags exactly that commit.  Annotated tags will always
 168 be preferred over lightweight tags, and tags with newer dates will
 169 always be preferred over tags with older dates.  If an exact match
 170 is found, its name will be output and searching will stop.
 171
 172 If an exact match was not found, 'git describe' will walk back
 173 through the commit history to locate an ancestor commit which
 174 has been tagged.  The ancestor's tag will be output along with an
 175 abbreviation of the input commit-ish's SHA-1. If `--first-parent` was
 176 specified then the walk will only consider the first parent of each
 177 commit.
 178
 179 If multiple tags were found during the walk then the tag which
 180 has the fewest commits different from the input commit-ish will be
 181 selected and output.  Here fewest commits different is defined as
 182 the number of commits which would be shown by `git log tag..input`
 183 will be the smallest number of commits possible.
 184
 185 GIT
 186 ---
 187 Part of the linkgit:git[1] suite