Documentation / git-tag.txton commit prio-queue: factor out compare and swap operations (6d63baa)
   1git-tag(1)
   2==========
   3
   4NAME
   5----
   6git-tag - Create, list, delete or verify a tag object signed with GPG
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git tag' [-a | -s | -u <key-id>] [-f] [-m <msg> | -F <file>]
  13        <tagname> [<commit> | <object>]
  14'git tag' -d <tagname>...
  15'git tag' [-n[<num>]] -l [--contains <commit>] [--points-at <object>]
  16        [--column[=<options>] | --no-column] [<pattern>...]
  17        [<pattern>...]
  18'git tag' -v <tagname>...
  19
  20DESCRIPTION
  21-----------
  22
  23Add a tag reference in `refs/tags/`, unless `-d/-l/-v` is given
  24to delete, list or verify tags.
  25
  26Unless `-f` is given, the named tag must not yet exist.
  27
  28If one of `-a`, `-s`, or `-u <key-id>` is passed, the command
  29creates a 'tag' object, and requires a tag message.  Unless
  30`-m <msg>` or `-F <file>` is given, an editor is started for the user to type
  31in the tag message.
  32
  33If `-m <msg>` or `-F <file>` is given and `-a`, `-s`, and `-u <key-id>`
  34are absent, `-a` is implied.
  35
  36Otherwise just a tag reference for the SHA-1 object name of the commit object is
  37created (i.e. a lightweight tag).
  38
  39A GnuPG signed tag object will be created when `-s` or `-u
  40<key-id>` is used.  When `-u <key-id>` is not used, the
  41committer identity for the current user is used to find the
  42GnuPG key for signing.  The configuration variable `gpg.program`
  43is used to specify custom GnuPG binary.
  44
  45Tag objects (created with `-a`, `s`, or `-u`) are called "annotated"
  46tags; they contain a creation date, the tagger name and e-mail, a
  47tagging message, and an optional GnuPG signature. Whereas a
  48"lightweight" tag is simply a name for an object (usually a commit
  49object).
  50
  51Annotated tags are meant for release while lightweight tags are meant
  52for private or temporary object labels. For this reason, some git
  53commands for naming objects (like `git describe`) will ignore
  54lightweight tags by default.
  55
  56
  57OPTIONS
  58-------
  59-a::
  60--annotate::
  61        Make an unsigned, annotated tag object
  62
  63-s::
  64--sign::
  65        Make a GPG-signed tag, using the default e-mail address's key.
  66
  67-u <key-id>::
  68--local-user=<key-id>::
  69        Make a GPG-signed tag, using the given key.
  70
  71-f::
  72--force::
  73        Replace an existing tag with the given name (instead of failing)
  74
  75-d::
  76--delete::
  77        Delete existing tags with the given names.
  78
  79-v::
  80--verify::
  81        Verify the gpg signature of the given tag names.
  82
  83-n<num>::
  84        <num> specifies how many lines from the annotation, if any,
  85        are printed when using -l.
  86        The default is not to print any annotation lines.
  87        If no number is given to `-n`, only the first line is printed.
  88        If the tag is not annotated, the commit message is displayed instead.
  89
  90-l <pattern>::
  91--list <pattern>::
  92        List tags with names that match the given pattern (or all if no
  93        pattern is given).  Running "git tag" without arguments also
  94        lists all tags. The pattern is a shell wildcard (i.e., matched
  95        using fnmatch(3)).  Multiple patterns may be given; if any of
  96        them matches, the tag is shown.
  97
  98--sort=<type>::
  99        Sort in a specific order. Supported type is "refname"
 100        (lexicographic order), "version:refname" or "v:refname" (tag
 101        names are treated as versions). Prepend "-" to reverse sort
 102        order.
 103
 104--column[=<options>]::
 105--no-column::
 106        Display tag listing in columns. See configuration variable
 107        column.tag for option syntax.`--column` and `--no-column`
 108        without options are equivalent to 'always' and 'never' respectively.
 109+
 110This option is only applicable when listing tags without annotation lines.
 111
 112--contains [<commit>]::
 113        Only list tags which contain the specified commit (HEAD if not
 114        specified).
 115
 116--points-at <object>::
 117        Only list tags of the given object.
 118
 119-m <msg>::
 120--message=<msg>::
 121        Use the given tag message (instead of prompting).
 122        If multiple `-m` options are given, their values are
 123        concatenated as separate paragraphs.
 124        Implies `-a` if none of `-a`, `-s`, or `-u <key-id>`
 125        is given.
 126
 127-F <file>::
 128--file=<file>::
 129        Take the tag message from the given file.  Use '-' to
 130        read the message from the standard input.
 131        Implies `-a` if none of `-a`, `-s`, or `-u <key-id>`
 132        is given.
 133
 134--cleanup=<mode>::
 135        This option sets how the tag message is cleaned up.
 136        The  '<mode>' can be one of 'verbatim', 'whitespace' and 'strip'.  The
 137        'strip' mode is default. The 'verbatim' mode does not change message at
 138        all, 'whitespace' removes just leading/trailing whitespace lines and
 139        'strip' removes both whitespace and commentary.
 140
 141<tagname>::
 142        The name of the tag to create, delete, or describe.
 143        The new tag name must pass all checks defined by
 144        linkgit:git-check-ref-format[1].  Some of these checks
 145        may restrict the characters allowed in a tag name.
 146
 147<commit>::
 148<object>::
 149        The object that the new tag will refer to, usually a commit.
 150        Defaults to HEAD.
 151
 152
 153CONFIGURATION
 154-------------
 155By default, 'git tag' in sign-with-default mode (-s) will use your
 156committer identity (of the form "Your Name <\your@email.address>") to
 157find a key.  If you want to use a different default key, you can specify
 158it in the repository configuration as follows:
 159
 160-------------------------------------
 161[user]
 162    signingkey = <gpg-key-id>
 163-------------------------------------
 164
 165
 166DISCUSSION
 167----------
 168
 169On Re-tagging
 170~~~~~~~~~~~~~
 171
 172What should you do when you tag a wrong commit and you would
 173want to re-tag?
 174
 175If you never pushed anything out, just re-tag it. Use "-f" to
 176replace the old one. And you're done.
 177
 178But if you have pushed things out (or others could just read
 179your repository directly), then others will have already seen
 180the old tag. In that case you can do one of two things:
 181
 182. The sane thing.
 183Just admit you screwed up, and use a different name. Others have
 184already seen one tag-name, and if you keep the same name, you
 185may be in the situation that two people both have "version X",
 186but they actually have 'different' "X"'s.  So just call it "X.1"
 187and be done with it.
 188
 189. The insane thing.
 190You really want to call the new version "X" too, 'even though'
 191others have already seen the old one. So just use 'git tag -f'
 192again, as if you hadn't already published the old one.
 193
 194However, Git does *not* (and it should not) change tags behind
 195users back. So if somebody already got the old tag, doing a
 196'git pull' on your tree shouldn't just make them overwrite the old
 197one.
 198
 199If somebody got a release tag from you, you cannot just change
 200the tag for them by updating your own one. This is a big
 201security issue, in that people MUST be able to trust their
 202tag-names.  If you really want to do the insane thing, you need
 203to just fess up to it, and tell people that you messed up. You
 204can do that by making a very public announcement saying:
 205
 206------------
 207Ok, I messed up, and I pushed out an earlier version tagged as X. I
 208then fixed something, and retagged the *fixed* tree as X again.
 209
 210If you got the wrong tag, and want the new one, please delete
 211the old one and fetch the new one by doing:
 212
 213        git tag -d X
 214        git fetch origin tag X
 215
 216to get my updated tag.
 217
 218You can test which tag you have by doing
 219
 220        git rev-parse X
 221
 222which should return 0123456789abcdef.. if you have the new version.
 223
 224Sorry for the inconvenience.
 225------------
 226
 227Does this seem a bit complicated?  It *should* be. There is no
 228way that it would be correct to just "fix" it automatically.
 229People need to know that their tags might have been changed.
 230
 231
 232On Automatic following
 233~~~~~~~~~~~~~~~~~~~~~~
 234
 235If you are following somebody else's tree, you are most likely
 236using remote-tracking branches (`refs/heads/origin` in traditional
 237layout, or `refs/remotes/origin/master` in the separate-remote
 238layout).  You usually want the tags from the other end.
 239
 240On the other hand, if you are fetching because you would want a
 241one-shot merge from somebody else, you typically do not want to
 242get tags from there.  This happens more often for people near
 243the toplevel but not limited to them.  Mere mortals when pulling
 244from each other do not necessarily want to automatically get
 245private anchor point tags from the other person.
 246
 247Often, "please pull" messages on the mailing list just provide
 248two pieces of information: a repo URL and a branch name; this
 249is designed to be easily cut&pasted at the end of a 'git fetch'
 250command line:
 251
 252------------
 253Linus, please pull from
 254
 255        git://git..../proj.git master
 256
 257to get the following updates...
 258------------
 259
 260becomes:
 261
 262------------
 263$ git pull git://git..../proj.git master
 264------------
 265
 266In such a case, you do not want to automatically follow the other
 267person's tags.
 268
 269One important aspect of Git is its distributed nature, which
 270largely means there is no inherent "upstream" or
 271"downstream" in the system.  On the face of it, the above
 272example might seem to indicate that the tag namespace is owned
 273by the upper echelon of people and that tags only flow downwards, but
 274that is not the case.  It only shows that the usage pattern
 275determines who are interested in whose tags.
 276
 277A one-shot pull is a sign that a commit history is now crossing
 278the boundary between one circle of people (e.g. "people who are
 279primarily interested in the networking part of the kernel") who may
 280have their own set of tags (e.g. "this is the third release
 281candidate from the networking group to be proposed for general
 282consumption with 2.6.21 release") to another circle of people
 283(e.g. "people who integrate various subsystem improvements").
 284The latter are usually not interested in the detailed tags used
 285internally in the former group (that is what "internal" means).
 286That is why it is desirable not to follow tags automatically in
 287this case.
 288
 289It may well be that among networking people, they may want to
 290exchange the tags internal to their group, but in that workflow
 291they are most likely tracking each other's progress by
 292having remote-tracking branches.  Again, the heuristic to automatically
 293follow such tags is a good thing.
 294
 295
 296On Backdating Tags
 297~~~~~~~~~~~~~~~~~~
 298
 299If you have imported some changes from another VCS and would like
 300to add tags for major releases of your work, it is useful to be able
 301to specify the date to embed inside of the tag object; such data in
 302the tag object affects, for example, the ordering of tags in the
 303gitweb interface.
 304
 305To set the date used in future tag objects, set the environment
 306variable GIT_COMMITTER_DATE (see the later discussion of possible
 307values; the most common form is "YYYY-MM-DD HH:MM").
 308
 309For example:
 310
 311------------
 312$ GIT_COMMITTER_DATE="2006-10-02 10:31" git tag -s v1.0.1
 313------------
 314
 315include::date-formats.txt[]
 316
 317SEE ALSO
 318--------
 319linkgit:git-check-ref-format[1].
 320
 321GIT
 322---
 323Part of the linkgit:git[1] suite