[thirdparty/git.git] / Documentation / git-tag.txt

git-tag(1)
==========

NAME
----
git-tag - Create, list, delete or verify a tag object signed with GPG


SYNOPSIS
--------
[verse]
'git-tag' [-a | -s | -u <key-id>] [-f] [-m <msg> | -F <file>]  <name> [<head>]
'git-tag' -d <name>...
'git-tag' [-n [<num>]] -l [<pattern>]
'git-tag' -v <name>...

DESCRIPTION
-----------
Adds a 'tag' reference in `.git/refs/tags/`

Unless `-f` is given, the tag must not yet exist in
`.git/refs/tags/` directory.

If one of `-a`, `-s`, or `-u <key-id>` is passed, the command
creates a 'tag' object, and requires the tag message.  Unless
`-m <msg>` or `-F <file>` is given, an editor is started for the user to type
in the tag message.

Otherwise just the SHA1 object name of the commit object is
written (i.e. a lightweight tag).

A GnuPG signed tag object will be created when `-s` or `-u
<key-id>` is used.  When `-u <key-id>` is not used, the
committer identity for the current user is used to find the
GnuPG key for signing.

OPTIONS
-------
-a::
	Make an unsigned, annotated tag object

-s::
	Make a GPG-signed tag, using the default e-mail address's key

-u <key-id>::
	Make a GPG-signed tag, using the given key

-f::
	Replace an existing tag with the given name (instead of failing)

-d::
	Delete existing tags with the given names.

-v::
	Verify the gpg signature of the given tag names.

-n <num>::
	<num> specifies how many lines from the annotation, if any,
	are printed when using -l.
	The default is not to print any annotation lines.
	If no number is given to `-n`, only the first line is printed.

-l <pattern>::
	List tags with names that match the given pattern (or all if no pattern is given).
	Typing "git tag" without arguments, also lists all tags.

-m <msg>::
	Use the given tag message (instead of prompting).
	If multiple `-m` options are given, there values are
	concatenated as separate paragraphs.

-F <file>::
	Take the tag message from the given file.  Use '-' to
	read the message from the standard input.

CONFIGURATION
-------------
By default, git-tag in sign-with-default mode (-s) will use your
committer identity (of the form "Your Name <your@email.address>") to
find a key.  If you want to use a different default key, you can specify
it in the repository configuration as follows:

-------------------------------------
[user]
    signingkey = <gpg-key-id>
-------------------------------------


DISCUSSION
----------

On Re-tagging
~~~~~~~~~~~~~

What should you do when you tag a wrong commit and you would
want to re-tag?

If you never pushed anything out, just re-tag it. Use "-f" to
replace the old one. And you're done.

But if you have pushed things out (or others could just read
your repository directly), then others will have already seen
the old tag. In that case you can do one of two things:

. The sane thing.
Just admit you screwed up, and use a different name. Others have
already seen one tag-name, and if you keep the same name, you
may be in the situation that two people both have "version X",
but they actually have 'different' "X"'s.  So just call it "X.1"
and be done with it.

. The insane thing.
You really want to call the new version "X" too, 'even though'
others have already seen the old one. So just use "git tag -f"
again, as if you hadn't already published the old one.

However, Git does *not* (and it should not) change tags behind
users back. So if somebody already got the old tag, doing a "git
pull" on your tree shouldn't just make them overwrite the old
one.

If somebody got a release tag from you, you cannot just change
the tag for them by updating your own one. This is a big
security issue, in that people MUST be able to trust their
tag-names.  If you really want to do the insane thing, you need
to just fess up to it, and tell people that you messed up. You
can do that by making a very public announcement saying:

------------
Ok, I messed up, and I pushed out an earlier version tagged as X. I
then fixed something, and retagged the *fixed* tree as X again.

If you got the wrong tag, and want the new one, please delete
the old one and fetch the new one by doing:

	git tag -d X
	git fetch origin tag X

to get my updated tag.

You can test which tag you have by doing

	git rev-parse X

which should return 0123456789abcdef.. if you have the new version.

Sorry for inconvenience.
------------

Does this seem a bit complicated?  It *should* be. There is no
way that it would be correct to just "fix" it behind peoples
backs. People need to know that their tags might have been
changed.


On Automatic following
~~~~~~~~~~~~~~~~~~~~~~

If you are following somebody else's tree, you are most likely
using tracking branches (`refs/heads/origin` in traditional
layout, or `refs/remotes/origin/master` in the separate-remote
layout).  You usually want the tags from the other end.

On the other hand, if you are fetching because you would want a
one-shot merge from somebody else, you typically do not want to
get tags from there.  This happens more often for people near
the toplevel but not limited to them.  Mere mortals when pulling
from each other do not necessarily want to automatically get
private anchor point tags from the other person.

You would notice "please pull" messages on the mailing list says
repo URL and branch name alone.  This is designed to be easily
cut&pasted to "git fetch" command line:

------------
Linus, please pull from

	git://git..../proj.git master

to get the following updates...
------------

becomes:

------------
$ git pull git://git..../proj.git master
------------

In such a case, you do not want to automatically follow other's
tags.

One important aspect of git is it is distributed, and being
distributed largely means there is no inherent "upstream" or
"downstream" in the system.  On the face of it, the above
example might seem to indicate that the tag namespace is owned
by upper echelon of people and tags only flow downwards, but
that is not the case.  It only shows that the usage pattern
determines who are interested in whose tags.

A one-shot pull is a sign that a commit history is now crossing
the boundary between one circle of people (e.g. "people who are
primarily interested in networking part of the kernel") who may
have their own set of tags (e.g. "this is the third release
candidate from the networking group to be proposed for general
consumption with 2.6.21 release") to another circle of people
(e.g. "people who integrate various subsystem improvements").
The latter are usually not interested in the detailed tags used
internally in the former group (that is what "internal" means).
That is why it is desirable not to follow tags automatically in
this case.

It may well be that among networking people, they may want to
exchange the tags internal to their group, but in that workflow
they are most likely tracking with each other's progress by
having tracking branches.  Again, the heuristic to automatically
follow such tags is a good thing.


On Backdating Tags
~~~~~~~~~~~~~~~~~~

If you have imported some changes from another VCS and would like
to add tags for major releases of your work, it is useful to be able
to specify the date to embed inside of the tag object.  The data in
the tag object affects, for example, the ordering of tags in the
gitweb interface.

To set the date used in future tag objects, set the environment
variable GIT_AUTHOR_DATE to one or more of the date and time.  The
date and time can be specified in a number of ways; the most common
is "YYYY-MM-DD HH:MM".

An example follows.

------------
$ GIT_AUTHOR_DATE="2006-10-02 10:31" git tag -s v1.0.1
------------


Author
------
Written by Linus Torvalds <torvalds@osdl.org>,
Junio C Hamano <junkio@cox.net> and Chris Wright <chrisw@osdl.org>.

Documentation
--------------
Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.

GIT
---
Part of the linkgit:git[7] suite
Commit	Line	Data
215a7ad1 JH	1	git-tag(1)
215a7ad1 JH	2	==========
2cf565c5 DG	3
	4	NAME
	5	----
453c1e85	6	git-tag - Create, list, delete or verify a tag object signed with GPG
2cf565c5 DG	7
2cf565c5 DG	8
2cf565c5 DG	9	SYNOPSIS
2cf565c5 DG	10	--------
b867c7c2	11	[verse]
86b9e017	12	'git-tag' [-a \| -s \| -u <key-id>] [-f] [-m <msg> \| -F <file>] <name> [<head>]
453c1e85	13	'git-tag' -d <name>...
980ea5c5	14	'git-tag' [-n [<num>]] -l [<pattern>]
62e09ce9	15	'git-tag' -v <name>...
2cf565c5 DG	16
	17	DESCRIPTION
	18	-----------
b867c7c2	19	Adds a 'tag' reference in `.git/refs/tags/`
b7e438f9	20
bc162e40 LT	21	Unless `-f` is given, the tag must not yet exist in
bc162e40 LT	22	`.git/refs/tags/` directory.
b7e438f9	23
bc162e40 LT	24	If one of `-a`, `-s`, or `-u <key-id>` is passed, the command
bc162e40 LT	25	creates a 'tag' object, and requires the tag message. Unless
62e09ce9	26	`-m <msg>` or `-F <file>` is given, an editor is started for the user to type
bc162e40	27	in the tag message.
b7e438f9	28
bc162e40	29	Otherwise just the SHA1 object name of the commit object is
56b5e946	30	written (i.e. a lightweight tag).
bc162e40 LT	31
	32	A GnuPG signed tag object will be created when `-s` or `-u
	33	<key-id>` is used. When `-u <key-id>` is not used, the
	34	committer identity for the current user is used to find the
	35	GnuPG key for signing.
2cf565c5	36
d839091d NW	37	OPTIONS
	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::
453c1e85	52	Delete existing tags with the given names.
d839091d	53
0bc72abd	54	-v::
62e09ce9	55	Verify the gpg signature of the given tag names.
0bc72abd	56
980ea5c5 MM	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.
62e09ce9	61	If no number is given to `-n`, only the first line is printed.
980ea5c5	62
b867c7c2	63	-l <pattern>::
980ea5c5	64	List tags with names that match the given pattern (or all if no pattern is given).
62e09ce9	65	Typing "git tag" without arguments, also lists all tags.
b867c7c2	66
d839091d	67	-m <msg>::
bd46c9a9 JH	68	Use the given tag message (instead of prompting).
	69	If multiple `-m` options are given, there values are
	70	concatenated as separate paragraphs.
d839091d	71
f79c73ce JS	72	-F <file>::
	73	Take the tag message from the given file. Use '-' to
	74	read the message from the standard input.
2cf565c5	75
d67778ec AP	76	CONFIGURATION
	77	-------------
	78	By default, git-tag in sign-with-default mode (-s) will use your
	79	committer identity (of the form "Your Name <your@email.address>") to
	80	find a key. If you want to use a different default key, you can specify
	81	it in the repository configuration as follows:
	82
86b9e017	83	-------------------------------------
d67778ec AP	84	[user]
d67778ec AP	85	signingkey = <gpg-key-id>
86b9e017	86	-------------------------------------
d67778ec	87
4853534e JH	88
	89	DISCUSSION
	90	----------
	91
	92	On Re-tagging
	93	~~~~~~~~~~~~~
	94
	95	What should you do when you tag a wrong commit and you would
	96	want to re-tag?
	97
	98	If you never pushed anything out, just re-tag it. Use "-f" to
	99	replace the old one. And you're done.
	100
	101	But if you have pushed things out (or others could just read
	102	your repository directly), then others will have already seen
	103	the old tag. In that case you can do one of two things:
	104
	105	. The sane thing.
	106	Just admit you screwed up, and use a different name. Others have
	107	already seen one tag-name, and if you keep the same name, you
	108	may be in the situation that two people both have "version X",
	109	but they actually have 'different' "X"'s. So just call it "X.1"
	110	and be done with it.
	111
	112	. The insane thing.
	113	You really want to call the new version "X" too, 'even though'
	114	others have already seen the old one. So just use "git tag -f"
	115	again, as if you hadn't already published the old one.
	116
06ada152	117	However, Git does not (and it should not) change tags behind
4853534e JH	118	users back. So if somebody already got the old tag, doing a "git
	119	pull" on your tree shouldn't just make them overwrite the old
	120	one.
	121
	122	If somebody got a release tag from you, you cannot just change
	123	the tag for them by updating your own one. This is a big
	124	security issue, in that people MUST be able to trust their
	125	tag-names. If you really want to do the insane thing, you need
	126	to just fess up to it, and tell people that you messed up. You
	127	can do that by making a very public announcement saying:
	128
	129	------------
	130	Ok, I messed up, and I pushed out an earlier version tagged as X. I
	131	then fixed something, and retagged the fixed tree as X again.
	132
	133	If you got the wrong tag, and want the new one, please delete
	134	the old one and fetch the new one by doing:
	135
	136	git tag -d X
	137	git fetch origin tag X
	138
	139	to get my updated tag.
	140
	141	You can test which tag you have by doing
	142
	143	git rev-parse X
	144
	145	which should return 0123456789abcdef.. if you have the new version.
	146
	147	Sorry for inconvenience.
	148	------------
	149
	150	Does this seem a bit complicated? It should be. There is no
	151	way that it would be correct to just "fix" it behind peoples
	152	backs. People need to know that their tags might have been
	153	changed.
	154
	155
	156	On Automatic following
	157	~~~~~~~~~~~~~~~~~~~~~~
	158
	159	If you are following somebody else's tree, you are most likely
	160	using tracking branches (`refs/heads/origin` in traditional
	161	layout, or `refs/remotes/origin/master` in the separate-remote
	162	layout). You usually want the tags from the other end.
	163
	164	On the other hand, if you are fetching because you would want a
	165	one-shot merge from somebody else, you typically do not want to
	166	get tags from there. This happens more often for people near
	167	the toplevel but not limited to them. Mere mortals when pulling
	168	from each other do not necessarily want to automatically get
	169	private anchor point tags from the other person.
	170
	171	You would notice "please pull" messages on the mailing list says
	172	repo URL and branch name alone. This is designed to be easily
	173	cut&pasted to "git fetch" command line:
	174
	175	------------
	176	Linus, please pull from
	177
	178	git://git..../proj.git master
	179
	180	to get the following updates...
	181	------------
182
183	becomes:
184
185	------------
186	$ git pull git://git..../proj.git master
187	------------
188
189	In such a case, you do not want to automatically follow other's
190	tags.
191
192	One important aspect of git is it is distributed, and being
193	distributed largely means there is no inherent "upstream" or
194	"downstream" in the system. On the face of it, the above
195	example might seem to indicate that the tag namespace is owned
196	by upper echelon of people and tags only flow downwards, but
197	that is not the case. It only shows that the usage pattern
198	determines who are interested in whose tags.
199
200	A one-shot pull is a sign that a commit history is now crossing
201	the boundary between one circle of people (e.g. "people who are
202	primarily interested in networking part of the kernel") who may
203	have their own set of tags (e.g. "this is the third release
204	candidate from the networking group to be proposed for general
205	consumption with 2.6.21 release") to another circle of people
206	(e.g. "people who integrate various subsystem improvements").
207	The latter are usually not interested in the detailed tags used
208	internally in the former group (that is what "internal" means).
209	That is why it is desirable not to follow tags automatically in
210	this case.
211
212	It may well be that among networking people, they may want to
213	exchange the tags internal to their group, but in that workflow
214	they are most likely tracking with each other's progress by
215	having tracking branches. Again, the heuristic to automatically
216	follow such tags is a good thing.
217
218
5040beff MO	219	On Backdating Tags
	220	~~~~~~~~~~~~~~~~~~
	221
	222	If you have imported some changes from another VCS and would like
	223	to add tags for major releases of your work, it is useful to be able
	224	to specify the date to embed inside of the tag object. The data in
	225	the tag object affects, for example, the ordering of tags in the
	226	gitweb interface.
	227
	228	To set the date used in future tag objects, set the environment
	229	variable GIT_AUTHOR_DATE to one or more of the date and time. The
	230	date and time can be specified in a number of ways; the most common
	231	is "YYYY-MM-DD HH:MM".
	232
	233	An example follows.
	234
	235	------------
	236	$ GIT_AUTHOR_DATE="2006-10-02 10:31" git tag -s v1.0.1
	237	------------
	238
	239
2cf565c5 DG	240	Author
2cf565c5 DG	241	------
3f971fc4 JH	242	Written by Linus Torvalds <torvalds@osdl.org>,
3f971fc4 JH	243	Junio C Hamano <junkio@cox.net> and Chris Wright <chrisw@osdl.org>.
2cf565c5 DG	244
	245	Documentation
	246	--------------
	247	Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
	248
	249	GIT
	250	---
5162e697	251	Part of the linkgit:git[7] suite