gitweb: Fix mimetype_guess_file for files with multiple extensions
[git/git.git] / Documentation / hooks.txt
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72e9340c 1Hooks used by git
6d35cc76 2=================
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3
4Hooks are little scripts you can place in `$GIT_DIR/hooks`
5directory to trigger action at certain points. When
6`git-init-db` is run, a handful example hooks are copied in the
7`hooks` directory of the new repository, but by default they are
8all disabled. To enable a hook, make it executable with `chmod
9+x`.
10
11This document describes the currently defined hooks.
12
13applypatch-msg
14--------------
15
16This hook is invoked by `git-applypatch` script, which is
17typically invoked by `git-applymbox`. It takes a single
18parameter, the name of the file that holds the proposed commit
19log message. Exiting with non-zero status causes the
20'git-applypatch' to abort before applying the patch.
21
22The hook is allowed to edit the message file in place, and can
23be used to normalize the message into some project standard
24format (if the project has one). It can also be used to refuse
25the commit after inspecting the message file.
26
27The default applypatch-msg hook, when enabled, runs the
28commit-msg hook, if the latter is enabled.
29
30pre-applypatch
31--------------
32
33This hook is invoked by `git-applypatch` script, which is
34typically invoked by `git-applymbox`. It takes no parameter,
35and is invoked after the patch is applied, but before a commit
36is made. Exiting with non-zero status causes the working tree
37after application of the patch not committed.
38
39It can be used to inspect the current working tree and refuse to
40make a commit if it does not pass certain test.
41
42The default pre-applypatch hook, when enabled, runs the
43pre-commit hook, if the latter is enabled.
44
45post-applypatch
46---------------
47
48This hook is invoked by `git-applypatch` script, which is
49typically invoked by `git-applymbox`. It takes no parameter,
50and is invoked after the patch is applied and a commit is made.
51
52This hook is meant primarily for notification, and cannot affect
53the outcome of `git-applypatch`.
54
55pre-commit
56----------
57
215a7ad1 58This hook is invoked by `git-commit`, and can be bypassed
e1ccf53a 59with `\--no-verify` option. It takes no parameter, and is
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60invoked before obtaining the proposed commit log message and
61making a commit. Exiting with non-zero status from this script
215a7ad1 62causes the `git-commit` to abort.
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63
64The default pre-commit hook, when enabled, catches introduction
65of lines with trailing whitespaces and aborts the commit when
66a such line is found.
67
68commit-msg
69----------
70
215a7ad1 71This hook is invoked by `git-commit`, and can be bypassed
e1ccf53a 72with `\--no-verify` option. It takes a single parameter, the
6d35cc76 73name of the file that holds the proposed commit log message.
215a7ad1 74Exiting with non-zero status causes the `git-commit` to
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75abort.
76
77The hook is allowed to edit the message file in place, and can
78be used to normalize the message into some project standard
79format (if the project has one). It can also be used to refuse
80the commit after inspecting the message file.
81
82The default commit-msg hook, when enabled, detects duplicate
83Signed-off-by: lines, and aborts the commit when one is found.
84
85post-commit
86-----------
87
215a7ad1 88This hook is invoked by `git-commit`. It takes no
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89parameter, and is invoked after a commit is made.
90
91This hook is meant primarily for notification, and cannot affect
215a7ad1 92the outcome of `git-commit`.
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93
94The default post-commit hook, when enabled, demonstrates how to
95send out a commit notification e-mail.
96
97update
98------
99
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100This hook is invoked by `git-receive-pack` on the remote repository,
101which is happens when a `git push` is done on a local repository.
102Just before updating the ref on the remote repository, the update hook
37425065 103is invoked. Its exit status determines the success or failure of
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104the ref update.
105
106The hook executes once for each ref to be updated, and takes
107three parameters:
108 - the name of the ref being updated,
109 - the old object name stored in the ref,
110 - and the new objectname to be stored in the ref.
111
112A zero exit from the update hook allows the ref to be updated.
113Exiting with a non-zero status prevents `git-receive-pack`
114from updating the ref.
115
116This hook can be used to prevent 'forced' update on certain refs by
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117making sure that the object name is a commit object that is a
118descendant of the commit object named by the old object name.
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119That is, to enforce a "fast forward only" policy.
120
121It could also be used to log the old..new status. However, it
122does not know the entire set of branches, so it would end up
123firing one e-mail per ref when used naively, though.
124
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125Another use suggested on the mailing list is to use this hook to
126implement access control which is finer grained than the one
127based on filesystem group.
128
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129The standard output of this hook is sent to /dev/null; if you
130want to report something to the git-send-pack on the other end,
131you can redirect your output to your stderr.
132
6250ad1e 133
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134post-update
135-----------
136
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137This hook is invoked by `git-receive-pack` on the remote repository,
138which is happens when a `git push` is done on a local repository.
139It executes on the remote repository once after all the refs have
140been updated.
141
142It takes a variable number of parameters, each of which is the
143name of ref that was actually updated.
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144
145This hook is meant primarily for notification, and cannot affect
146the outcome of `git-receive-pack`.
147
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148The post-update hook can tell what are the heads that were pushed,
149but it does not know what their original and updated values are,
150so it is a poor place to do log old..new.
151
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152The default post-update hook, when enabled, runs
153`git-update-server-info` to keep the information used by dumb
abda1ef5 154transports (e.g., http) up-to-date. If you are publishing
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155a git repository that is accessible via http, you should
156probably enable this hook.
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157
158The standard output of this hook is sent to /dev/null; if you
159want to report something to the git-send-pack on the other end,
160you can redirect your output to your stderr.