Documentation / git-tag.txton commit Tidy up git mergetool's backup file behaviour (44c36d1)
   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>]  <name> [<head>]
  13'git-tag' -d <name>...
  14'git-tag' [-n [<num>]] -l [<pattern>]
  15'git-tag' -v <name>...
  16
  17DESCRIPTION
  18-----------
  19Adds a 'tag' reference in `.git/refs/tags/`
  20
  21Unless `-f` is given, the tag must not yet exist in
  22`.git/refs/tags/` directory.
  23
  24If one of `-a`, `-s`, or `-u <key-id>` is passed, the command
  25creates a 'tag' object, and requires the tag message.  Unless
  26`-m <msg>` or `-F <file>` is given, an editor is started for the user to type
  27in the tag message.
  28
  29Otherwise just the SHA1 object name of the commit object is
  30written (i.e. a lightweight tag).
  31
  32A GnuPG signed tag object will be created when `-s` or `-u
  33<key-id>` is used.  When `-u <key-id>` is not used, the
  34committer identity for the current user is used to find the
  35GnuPG key for signing.
  36
  37OPTIONS
  38-------
  39-a::
  40        Make an unsigned, annotated tag object
  41
  42-s::
  43        Make a GPG-signed tag, using the default e-mail address's key
  44
  45-u <key-id>::
  46        Make a GPG-signed tag, using the given key
  47
  48-f::
  49        Replace an existing tag with the given name (instead of failing)
  50
  51-d::
  52        Delete existing tags with the given names.
  53
  54-v::
  55        Verify the gpg signature of the given tag names.
  56
  57-n <num>::
  58        <num> specifies how many lines from the annotation, if any,
  59        are printed when using -l.
  60        The default is not to print any annotation lines.
  61        If no number is given to `-n`, only the first line is printed.
  62
  63-l <pattern>::
  64        List tags with names that match the given pattern (or all if no pattern is given).
  65        Typing "git tag" without arguments, also lists all tags.
  66
  67-m <msg>::
  68        Use the given tag message (instead of prompting).
  69        If multiple `-m` options are given, there values are
  70        concatenated as separate paragraphs.
  71
  72-F <file>::
  73        Take the tag message from the given file.  Use '-' to
  74        read the message from the standard input.
  75
  76CONFIGURATION
  77-------------
  78By default, git-tag in sign-with-default mode (-s) will use your
  79committer identity (of the form "Your Name <your@email.address>") to
  80find a key.  If you want to use a different default key, you can specify
  81it in the repository configuration as follows:
  82
  83-------------------------------------
  84[user]
  85    signingkey = <gpg-key-id>
  86-------------------------------------
  87
  88
  89DISCUSSION
  90----------
  91
  92On Re-tagging
  93~~~~~~~~~~~~~
  94
  95What should you do when you tag a wrong commit and you would
  96want to re-tag?
  97
  98If you never pushed anything out, just re-tag it. Use "-f" to
  99replace the old one. And you're done.
 100
 101But if you have pushed things out (or others could just read
 102your repository directly), then others will have already seen
 103the old tag. In that case you can do one of two things:
 104
 105. The sane thing.
 106Just admit you screwed up, and use a different name. Others have
 107already seen one tag-name, and if you keep the same name, you
 108may be in the situation that two people both have "version X",
 109but they actually have 'different' "X"'s.  So just call it "X.1"
 110and be done with it.
 111
 112. The insane thing.
 113You really want to call the new version "X" too, 'even though'
 114others have already seen the old one. So just use "git tag -f"
 115again, as if you hadn't already published the old one.
 116
 117However, Git does *not* (and it should not) change tags behind
 118users back. So if somebody already got the old tag, doing a "git
 119pull" on your tree shouldn't just make them overwrite the old
 120one.
 121
 122If somebody got a release tag from you, you cannot just change
 123the tag for them by updating your own one. This is a big
 124security issue, in that people MUST be able to trust their
 125tag-names.  If you really want to do the insane thing, you need
 126to just fess up to it, and tell people that you messed up. You
 127can do that by making a very public announcement saying:
 128
 129------------
 130Ok, I messed up, and I pushed out an earlier version tagged as X. I
 131then fixed something, and retagged the *fixed* tree as X again.
 132
 133If you got the wrong tag, and want the new one, please delete
 134the old one and fetch the new one by doing:
 135
 136        git tag -d X
 137        git fetch origin tag X
 138
 139to get my updated tag.
 140
 141You can test which tag you have by doing
 142
 143        git rev-parse X
 144
 145which should return 0123456789abcdef.. if you have the new version.
 146
 147Sorry for inconvenience.
 148------------
 149
 150Does this seem a bit complicated?  It *should* be. There is no
 151way that it would be correct to just "fix" it behind peoples
 152backs. People need to know that their tags might have been
 153changed.
 154
 155
 156On Automatic following
 157~~~~~~~~~~~~~~~~~~~~~~
 158
 159If you are following somebody else's tree, you are most likely
 160using tracking branches (`refs/heads/origin` in traditional
 161layout, or `refs/remotes/origin/master` in the separate-remote
 162layout).  You usually want the tags from the other end.
 163
 164On the other hand, if you are fetching because you would want a
 165one-shot merge from somebody else, you typically do not want to
 166get tags from there.  This happens more often for people near
 167the toplevel but not limited to them.  Mere mortals when pulling
 168from each other do not necessarily want to automatically get
 169private anchor point tags from the other person.
 170
 171You would notice "please pull" messages on the mailing list says
 172repo URL and branch name alone.  This is designed to be easily
 173cut&pasted to "git fetch" command line:
 174
 175------------
 176Linus, please pull from
 177
 178        git://git..../proj.git master
 179
 180to get the following updates...
 181------------
 182
 183becomes:
 184
 185------------
 186$ git pull git://git..../proj.git master
 187------------
 188
 189In such a case, you do not want to automatically follow other's
 190tags.
 191
 192One important aspect of git is it is distributed, and being
 193distributed largely means there is no inherent "upstream" or
 194"downstream" in the system.  On the face of it, the above
 195example might seem to indicate that the tag namespace is owned
 196by upper echelon of people and tags only flow downwards, but
 197that is not the case.  It only shows that the usage pattern
 198determines who are interested in whose tags.
 199
 200A one-shot pull is a sign that a commit history is now crossing
 201the boundary between one circle of people (e.g. "people who are
 202primarily interested in networking part of the kernel") who may
 203have their own set of tags (e.g. "this is the third release
 204candidate from the networking group to be proposed for general
 205consumption with 2.6.21 release") to another circle of people
 206(e.g. "people who integrate various subsystem improvements").
 207The latter are usually not interested in the detailed tags used
 208internally in the former group (that is what "internal" means).
 209That is why it is desirable not to follow tags automatically in
 210this case.
 211
 212It may well be that among networking people, they may want to
 213exchange the tags internal to their group, but in that workflow
 214they are most likely tracking with each other's progress by
 215having tracking branches.  Again, the heuristic to automatically
 216follow such tags is a good thing.
 217
 218
 219On Backdating Tags
 220~~~~~~~~~~~~~~~~~~
 221
 222If you have imported some changes from another VCS and would like
 223to add tags for major releases of your work, it is useful to be able
 224to specify the date to embed inside of the tag object.  The data in
 225the tag object affects, for example, the ordering of tags in the
 226gitweb interface.
 227
 228To set the date used in future tag objects, set the environment
 229variable GIT_AUTHOR_DATE to one or more of the date and time.  The
 230date and time can be specified in a number of ways; the most common
 231is "YYYY-MM-DD HH:MM".
 232
 233An example follows.
 234
 235------------
 236$ GIT_AUTHOR_DATE="2006-10-02 10:31" git tag -s v1.0.1
 237------------
 238
 239
 240Author
 241------
 242Written by Linus Torvalds <torvalds@osdl.org>,
 243Junio C Hamano <junkio@cox.net> and Chris Wright <chrisw@osdl.org>.
 244
 245Documentation
 246--------------
 247Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
 248
 249GIT
 250---
 251Part of the linkgit:git[7] suite