notes: implement 'git notes copy --stdin'
[git/git.git] / Documentation / githooks.txt
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1githooks(5)
2===========
3
4NAME
5----
6githooks - Hooks used by git
7
8SYNOPSIS
9--------
10$GIT_DIR/hooks/*
11
12
13DESCRIPTION
14-----------
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15
16Hooks are little scripts you can place in `$GIT_DIR/hooks`
17directory to trigger action at certain points. When
0b444cdb 18'git init' is run, a handful of example hooks are copied into the
6d35cc76 19`hooks` directory of the new repository, but by default they are
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20all disabled. To enable a hook, rename it by removing its `.sample`
21suffix.
6d35cc76 22
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23NOTE: It is also a requirement for a given hook to be executable.
24However - in a freshly initialized repository - the `.sample` files are
25executable by default.
26
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27This document describes the currently defined hooks.
28
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29HOOKS
30-----
31
6d35cc76 32applypatch-msg
6d71c1dc 33~~~~~~~~~~~~~~
6d35cc76 34
0b444cdb 35This hook is invoked by 'git am' script. It takes a single
6d35cc76 36parameter, the name of the file that holds the proposed commit
45ad9b50 37log message. Exiting with non-zero status causes
0b444cdb 38'git am' to abort before applying the patch.
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39
40The hook is allowed to edit the message file in place, and can
41be used to normalize the message into some project standard
42format (if the project has one). It can also be used to refuse
43the commit after inspecting the message file.
44
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45The default 'applypatch-msg' hook, when enabled, runs the
46'commit-msg' hook, if the latter is enabled.
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47
48pre-applypatch
6d71c1dc 49~~~~~~~~~~~~~~
6d35cc76 50
0b444cdb 51This hook is invoked by 'git am'. It takes no parameter, and is
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52invoked after the patch is applied, but before a commit is made.
53
54If it exits with non-zero status, then the working tree will not be
55committed after applying the patch.
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56
57It can be used to inspect the current working tree and refuse to
58make a commit if it does not pass certain test.
59
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60The default 'pre-applypatch' hook, when enabled, runs the
61'pre-commit' hook, if the latter is enabled.
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62
63post-applypatch
6d71c1dc 64~~~~~~~~~~~~~~~
6d35cc76 65
0b444cdb 66This hook is invoked by 'git am'. It takes no parameter,
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67and is invoked after the patch is applied and a commit is made.
68
69This hook is meant primarily for notification, and cannot affect
0b444cdb 70the outcome of 'git am'.
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71
72pre-commit
6d71c1dc 73~~~~~~~~~~
6d35cc76 74
0b444cdb 75This hook is invoked by 'git commit', and can be bypassed
e1ccf53a 76with `\--no-verify` option. It takes no parameter, and is
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77invoked before obtaining the proposed commit log message and
78making a commit. Exiting with non-zero status from this script
0b444cdb 79causes the 'git commit' to abort.
6d35cc76 80
45ad9b50 81The default 'pre-commit' hook, when enabled, catches introduction
6d35cc76 82of lines with trailing whitespaces and aborts the commit when
45ad9b50 83such a line is found.
6d35cc76 84
0b444cdb 85All the 'git commit' hooks are invoked with the environment
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86variable `GIT_EDITOR=:` if the command will not bring up an editor
87to modify the commit message.
88
8089c85b 89prepare-commit-msg
6d71c1dc 90~~~~~~~~~~~~~~~~~~
8089c85b 91
0b444cdb 92This hook is invoked by 'git commit' right after preparing the
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93default log message, and before the editor is started.
94
95It takes one to three parameters. The first is the name of the file
99686960 96that contains the commit log message. The second is the source of the commit
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97message, and can be: `message` (if a `-m` or `-F` option was
98given); `template` (if a `-t` option was given or the
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99configuration option `commit.template` is set); `merge` (if the
100commit is a merge or a `.git/MERGE_MSG` file exists); `squash`
101(if a `.git/SQUASH_MSG` file exists); or `commit`, followed by
5d6b3a9e 102a commit SHA1 (if a `-c`, `-C` or `\--amend` option was given).
8089c85b 103
0b444cdb 104If the exit status is non-zero, 'git commit' will abort.
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105
106The purpose of the hook is to edit the message file in place, and
107it is not suppressed by the `\--no-verify` option. A non-zero exit
108means a failure of the hook and aborts the commit. It should not
109be used as replacement for pre-commit hook.
110
111The sample `prepare-commit-msg` hook that comes with git comments
112out the `Conflicts:` part of a merge's commit message.
113
6d35cc76 114commit-msg
6d71c1dc 115~~~~~~~~~~
6d35cc76 116
0b444cdb 117This hook is invoked by 'git commit', and can be bypassed
e1ccf53a 118with `\--no-verify` option. It takes a single parameter, the
6d35cc76 119name of the file that holds the proposed commit log message.
0b444cdb 120Exiting with non-zero status causes the 'git commit' to
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121abort.
122
123The hook is allowed to edit the message file in place, and can
124be used to normalize the message into some project standard
125format (if the project has one). It can also be used to refuse
126the commit after inspecting the message file.
127
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128The default 'commit-msg' hook, when enabled, detects duplicate
129"Signed-off-by" lines, and aborts the commit if one is found.
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130
131post-commit
6d71c1dc 132~~~~~~~~~~~
6d35cc76 133
0b444cdb 134This hook is invoked by 'git commit'. It takes no
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135parameter, and is invoked after a commit is made.
136
137This hook is meant primarily for notification, and cannot affect
0b444cdb 138the outcome of 'git commit'.
6d35cc76 139
00e5d48a 140pre-rebase
6d71c1dc 141~~~~~~~~~~
00e5d48a 142
0b444cdb 143This hook is called by 'git rebase' and can be used to prevent a branch
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144from getting rebased.
145
146
1abbe475 147post-checkout
6d71c1dc 148~~~~~~~~~~~~~
1abbe475 149
0b444cdb 150This hook is invoked when a 'git checkout' is run after having updated the
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151worktree. The hook is given three parameters: the ref of the previous HEAD,
152the ref of the new HEAD (which may or may not have changed), and a flag
153indicating whether the checkout was a branch checkout (changing branches,
154flag=1) or a file checkout (retrieving a file from the index, flag=0).
0b444cdb 155This hook cannot affect the outcome of 'git checkout'.
1abbe475 156
0b444cdb 157It is also run after 'git clone', unless the --no-checkout (-n) option is
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158used. The first parameter given to the hook is the null-ref, the second the
159ref of the new HEAD and the flag is always 1.
160
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161This hook can be used to perform repository validity checks, auto-display
162differences from the previous HEAD if different, or set working dir metadata
163properties.
164
46232915 165post-merge
6d71c1dc 166~~~~~~~~~~
46232915 167
0b444cdb 168This hook is invoked by 'git merge', which happens when a 'git pull'
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169is done on a local repository. The hook takes a single parameter, a status
170flag specifying whether or not the merge being done was a squash merge.
0b444cdb 171This hook cannot affect the outcome of 'git merge' and is not executed,
2b3e60c2 172if the merge failed due to conflicts.
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173
174This hook can be used in conjunction with a corresponding pre-commit hook to
175save and restore any form of metadata associated with the working tree
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176(eg: permissions/ownership, ACLS, etc). See contrib/hooks/setgitperms.perl
177for an example of how to do this.
46232915 178
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179[[pre-receive]]
180pre-receive
6d71c1dc 181~~~~~~~~~~~
cbb84e5d 182
ba020ef5 183This hook is invoked by 'git-receive-pack' on the remote repository,
0b444cdb 184which happens when a 'git push' is done on a local repository.
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185Just before starting to update refs on the remote repository, the
186pre-receive hook is invoked. Its exit status determines the success
187or failure of the update.
188
189This hook executes once for the receive operation. It takes no
190arguments, but for each ref to be updated it receives on standard
191input a line of the format:
192
193 <old-value> SP <new-value> SP <ref-name> LF
194
195where `<old-value>` is the old object name stored in the ref,
196`<new-value>` is the new object name to be stored in the ref and
197`<ref-name>` is the full name of the ref.
198When creating a new ref, `<old-value>` is 40 `0`.
199
200If the hook exits with non-zero status, none of the refs will be
201updated. If the hook exits with zero, updating of individual refs can
202still be prevented by the <<update,'update'>> hook.
203
24a0d61e 204Both standard output and standard error output are forwarded to
0b444cdb 205'git send-pack' on the other end, so you can simply `echo` messages
24a0d61e 206for the user.
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207
208[[update]]
6d35cc76 209update
6d71c1dc 210~~~~~~
6d35cc76 211
ba020ef5 212This hook is invoked by 'git-receive-pack' on the remote repository,
0b444cdb 213which happens when a 'git push' is done on a local repository.
6250ad1e 214Just before updating the ref on the remote repository, the update hook
37425065 215is invoked. Its exit status determines the success or failure of
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216the ref update.
217
218The hook executes once for each ref to be updated, and takes
219three parameters:
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220
221 - the name of the ref being updated,
222 - the old object name stored in the ref,
223 - and the new objectname to be stored in the ref.
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224
225A zero exit from the update hook allows the ref to be updated.
ba020ef5 226Exiting with a non-zero status prevents 'git-receive-pack'
cbb84e5d 227from updating that ref.
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228
229This hook can be used to prevent 'forced' update on certain refs by
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230making sure that the object name is a commit object that is a
231descendant of the commit object named by the old object name.
a75d7b54 232That is, to enforce a "fast-forward only" policy.
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233
234It could also be used to log the old..new status. However, it
235does not know the entire set of branches, so it would end up
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236firing one e-mail per ref when used naively, though. The
237<<post-receive,'post-receive'>> hook is more suited to that.
6250ad1e 238
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239Another use suggested on the mailing list is to use this hook to
240implement access control which is finer grained than the one
241based on filesystem group.
242
24a0d61e 243Both standard output and standard error output are forwarded to
0b444cdb 244'git send-pack' on the other end, so you can simply `echo` messages
24a0d61e 245for the user.
3aadad1b 246
cbb84e5d 247The default 'update' hook, when enabled--and with
39c448c1 248`hooks.allowunannotated` config option unset or set to false--prevents
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249unannotated tags to be pushed.
250
251[[post-receive]]
252post-receive
6d71c1dc 253~~~~~~~~~~~~
6250ad1e 254
ba020ef5 255This hook is invoked by 'git-receive-pack' on the remote repository,
0b444cdb 256which happens when a 'git push' is done on a local repository.
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257It executes on the remote repository once after all the refs have
258been updated.
259
260This hook executes once for the receive operation. It takes no
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261arguments, but gets the same information as the
262<<pre-receive,'pre-receive'>>
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263hook does on its standard input.
264
ba020ef5 265This hook does not affect the outcome of 'git-receive-pack', as it
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266is called after the real work is done.
267
02783075 268This supersedes the <<post-update,'post-update'>> hook in that it gets
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269both old and new values of all the refs in addition to their
270names.
cbb84e5d 271
24a0d61e 272Both standard output and standard error output are forwarded to
0b444cdb 273'git send-pack' on the other end, so you can simply `echo` messages
24a0d61e 274for the user.
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275
276The default 'post-receive' hook is empty, but there is
277a sample script `post-receive-email` provided in the `contrib/hooks`
278directory in git distribution, which implements sending commit
279emails.
280
281[[post-update]]
6d35cc76 282post-update
6d71c1dc 283~~~~~~~~~~~
6d35cc76 284
ba020ef5 285This hook is invoked by 'git-receive-pack' on the remote repository,
0b444cdb 286which happens when a 'git push' is done on a local repository.
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287It executes on the remote repository once after all the refs have
288been updated.
289
290It takes a variable number of parameters, each of which is the
291name of ref that was actually updated.
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292
293This hook is meant primarily for notification, and cannot affect
ba020ef5 294the outcome of 'git-receive-pack'.
6d35cc76 295
45ad9b50 296The 'post-update' hook can tell what are the heads that were pushed,
6250ad1e 297but it does not know what their original and updated values are,
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298so it is a poor place to do log old..new. The
299<<post-receive,'post-receive'>> hook does get both original and
300updated values of the refs. You might consider it instead if you need
301them.
cbb84e5d 302
45ad9b50 303When enabled, the default 'post-update' hook runs
0b444cdb 304'git update-server-info' to keep the information used by dumb
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305transports (e.g., HTTP) up-to-date. If you are publishing
306a git repository that is accessible via HTTP, you should
6250ad1e 307probably enable this hook.
3aadad1b 308
cbb84e5d 309Both standard output and standard error output are forwarded to
0b444cdb 310'git send-pack' on the other end, so you can simply `echo` messages
24a0d61e 311for the user.
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312
313pre-auto-gc
6d71c1dc 314~~~~~~~~~~~
0b85d926 315
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316This hook is invoked by 'git gc --auto'. It takes no parameter, and
317exiting with non-zero status from this script causes the 'git gc --auto'
0b85d926 318to abort.
a5af0e2c 319
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320post-rewrite
321~~~~~~~~~~~~
322
323This hook is invoked by commands that rewrite commits (`git commit
324--amend`, 'git-rebase'; currently 'git-filter-branch' does 'not' call
325it!). Its first argument denotes the command it was invoked by:
326currently one of `amend` or `rebase`. Further command-dependent
327arguments may be passed in the future.
328
329The hook receives a list of the rewritten commits on stdin, in the
330format
331
332 <old-sha1> SP <new-sha1> [ SP <extra-info> ] LF
333
334The 'extra-info' is again command-dependent. If it is empty, the
335preceding SP is also omitted. Currently, no commands pass any
336'extra-info'.
337
338The following command-specific comments apply:
339
340rebase::
341 For the 'squash' and 'fixup' operation, all commits that were
342 squashed are listed as being rewritten to the squashed commit.
343 This means that there will be several lines sharing the same
344 'new-sha1'.
345+
346The commits are guaranteed to be listed in the order that they were
347processed by rebase.
348
349There is no default 'post-rewrite' hook, but see the
350`post-receive-copy-notes` script in `contrib/hooks` for an example
351that copies your git-notes to the rewritten commits.
352
353
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354GIT
355---
9e1f0a85 356Part of the linkgit:git[1] suite