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diff --git a/Documentation/git-describe.txt b/Documentation/git-describe.txt new file mode 100644 index 0000000000..a88f6ae2c6 --- /dev/null +++ b/Documentation/git-describe.txt @@ -0,0 +1,207 @@ +git-describe(1) +=============== + +NAME +---- +git-describe - Give an object a human readable name based on an available ref + +SYNOPSIS +-------- +[verse] +'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] [<commit-ish>...] +'git describe' [--all] [--tags] [--contains] [--abbrev=<n>] --dirty[=<mark>] +'git describe' <blob> + +DESCRIPTION +----------- +The command finds the most recent tag that is reachable from a +commit. If the tag points to the commit, then only the tag is +shown. Otherwise, it suffixes the tag name with the number of +additional commits on top of the tagged object and the +abbreviated object name of the most recent commit. The result +is a "human-readable" object name which can also be used to +identify the commit to other git commands. + +By default (without --all or --tags) `git describe` only shows +annotated tags. For more information about creating annotated tags +see the -a and -s options to linkgit:git-tag[1]. + +If the given object refers to a blob, it will be described +as `<commit-ish>:<path>`, such that the blob can be found +at `<path>` in the `<commit-ish>`, which itself describes the +first commit in which this blob occurs in a reverse revision walk +from HEAD. + +OPTIONS +------- +<commit-ish>...:: + Commit-ish object names to describe. Defaults to HEAD if omitted. + +--dirty[=<mark>]:: +--broken[=<mark>]:: + Describe the state of the working tree. When the working + tree matches HEAD, the output is the same as "git describe + HEAD". If the working tree has local modification "-dirty" + is appended to it. If a repository is corrupt and Git + cannot determine if there is local modification, Git will + error out, unless `--broken' is given, which appends + the suffix "-broken" instead. + +--all:: + Instead of using only the annotated tags, use any ref + found in `refs/` namespace. This option enables matching + any known branch, remote-tracking branch, or lightweight tag. + +--tags:: + Instead of using only the annotated tags, use any tag + found in `refs/tags` namespace. This option enables matching + a lightweight (non-annotated) tag. + +--contains:: + Instead of finding the tag that predates the commit, find + the tag that comes after the commit, and thus contains it. + Automatically implies --tags. + +--abbrev=<n>:: + Instead of using the default 7 hexadecimal digits as the + abbreviated object name, use <n> digits, or as many digits + as needed to form a unique object name. An <n> of 0 + will suppress long format, only showing the closest tag. + +--candidates=<n>:: + Instead of considering only the 10 most recent tags as + candidates to describe the input commit-ish consider + up to <n> candidates. Increasing <n> above 10 will take + slightly longer but may produce a more accurate result. + An <n> of 0 will cause only exact matches to be output. + +--exact-match:: + Only output exact matches (a tag directly references the + supplied commit). This is a synonym for --candidates=0. + +--debug:: + Verbosely display information about the searching strategy + being employed to standard error. The tag name will still + be printed to standard out. + +--long:: + Always output the long format (the tag, the number of commits + and the abbreviated commit name) even when it matches a tag. + This is useful when you want to see parts of the commit object name + in "describe" output, even when the commit in question happens to be + a tagged version. Instead of just emitting the tag name, it will + describe such a commit as v1.2-0-gdeadbee (0th commit since tag v1.2 + that points at object deadbee....). + +--match <pattern>:: + Only consider tags matching the given `glob(7)` pattern, + excluding the "refs/tags/" prefix. If used with `--all`, it also + considers local branches and remote-tracking references matching the + pattern, excluding respectively "refs/heads/" and "refs/remotes/" + prefix; references of other types are never considered. If given + multiple times, a list of patterns will be accumulated, and tags + matching any of the patterns will be considered. Use `--no-match` to + clear and reset the list of patterns. + +--exclude <pattern>:: + Do not consider tags matching the given `glob(7)` pattern, excluding + the "refs/tags/" prefix. If used with `--all`, it also does not consider + local branches and remote-tracking references matching the pattern, + excluding respectively "refs/heads/" and "refs/remotes/" prefix; + references of other types are never considered. If given multiple times, + a list of patterns will be accumulated and tags matching any of the + patterns will be excluded. When combined with --match a tag will be + considered when it matches at least one --match pattern and does not + match any of the --exclude patterns. Use `--no-exclude` to clear and + reset the list of patterns. + +--always:: + Show uniquely abbreviated commit object as fallback. + +--first-parent:: + Follow only the first parent commit upon seeing a merge commit. + This is useful when you wish to not match tags on branches merged + in the history of the target commit. + +EXAMPLES +-------- + +With something like git.git current tree, I get: + + [torvalds@g5 git]$ git describe parent + v1.0.4-14-g2414721 + +i.e. the current head of my "parent" branch is based on v1.0.4, +but since it has a few commits on top of that, +describe has added the number of additional commits ("14") and +an abbreviated object name for the commit itself ("2414721") +at the end. + +The number of additional commits is the number +of commits which would be displayed by "git log v1.0.4..parent". +The hash suffix is "-g" + unambiguous abbreviation for the tip commit +of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`). +The "g" prefix stands for "git" and is used to allow describing the version of +a software depending on the SCM the software is managed with. This is useful +in an environment where people may use different SCMs. + +Doing a 'git describe' on a tag-name will just show the tag name: + + [torvalds@g5 git]$ git describe v1.0.4 + v1.0.4 + +With --all, the command can use branch heads as references, so +the output shows the reference path as well: + + [torvalds@g5 git]$ git describe --all --abbrev=4 v1.0.5^2 + tags/v1.0.0-21-g975b + + [torvalds@g5 git]$ git describe --all --abbrev=4 HEAD^ + heads/lt/describe-7-g975b + +With --abbrev set to 0, the command can be used to find the +closest tagname without any suffix: + + [torvalds@g5 git]$ git describe --abbrev=0 v1.0.5^2 + tags/v1.0.0 + +Note that the suffix you get if you type these commands today may be +longer than what Linus saw above when he ran these commands, as your +Git repository may have new commits whose object names begin with +975b that did not exist back then, and "-g975b" suffix alone may not +be sufficient to disambiguate these commits. + + +SEARCH STRATEGY +--------------- + +For each commit-ish supplied, 'git describe' will first look for +a tag which tags exactly that commit. Annotated tags will always +be preferred over lightweight tags, and tags with newer dates will +always be preferred over tags with older dates. If an exact match +is found, its name will be output and searching will stop. + +If an exact match was not found, 'git describe' will walk back +through the commit history to locate an ancestor commit which +has been tagged. The ancestor's tag will be output along with an +abbreviation of the input commit-ish's SHA-1. If `--first-parent` was +specified then the walk will only consider the first parent of each +commit. + +If multiple tags were found during the walk then the tag which +has the fewest commits different from the input commit-ish will be +selected and output. Here fewest commits different is defined as +the number of commits which would be shown by `git log tag..input` +will be the smallest number of commits possible. + +BUGS +---- + +Tree objects as well as tag objects not pointing at commits, cannot be described. +When describing blobs, the lightweight tags pointing at blobs are ignored, +but the blob is still described as <committ-ish>:<path> despite the lightweight +tag being favorable. + +GIT +--- +Part of the linkgit:git[1] suite |