GITHOOKS(5)GITHOOKS(5)NAMEgithooks - Hooks used by git
SYNOPSIS
$GIT_DIR/hooks/*
DESCRIPTION
Hooks are little scripts you can place in $GIT_DIR/hooks directory to
trigger action at certain points. When git init is run, a handful of
example hooks are copied into the hooks directory of the new reposi-
tory, but by default they are all disabled. To enable a hook, rename it
by removing its .sample suffix.
Note
It is also a requirement for a given hook to be executable. How-
ever - in a freshly initialized repository - the .sample files
are executable by default.
This document describes the currently defined hooks.
HOOKS
applypatch-msg
This hook is invoked by git am script. It takes a single parameter, the
name of the file that holds the proposed commit log message. Exiting
with non-zero status causes git am to abort before applying the patch.
The hook is allowed to edit the message file in place, and can be used
to normalize the message into some project standard format (if the pro-
ject has one). It can also be used to refuse the commit after inspect-
ing the message file.
The default applypatch-msg hook, when enabled, runs the commit-msg
hook, if the latter is enabled.
pre-applypatch
This hook is invoked by git am. It takes no parameter, and is invoked
after the patch is applied, but before a commit is made.
If it exits with non-zero status, then the working tree will not be
committed after applying the patch.
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It can be used to inspect the current working tree and refuse to make a
commit if it does not pass certain test.
The default pre-applypatch hook, when enabled, runs the pre-commit
hook, if the latter is enabled.
post-applypatch
This hook is invoked by git am. It takes no parameter, and is invoked
after the patch is applied and a commit is made.
This hook is meant primarily for notification, and cannot affect the
outcome of git am.
pre-commit
This hook is invoked by git commit, and can be bypassed with \--no-ver-
ify option. It takes no parameter, and is invoked before obtaining the
proposed commit log message and making a commit. Exiting with non-zero
status from this script causes the git commit to abort.
The default pre-commit hook, when enabled, catches introduction of
lines with trailing whitespaces and aborts the commit when such a line
is found.
All the git commit hooks are invoked with the environment variable
GIT_EDITOR=: if the command will not bring up an editor to modify the
commit message.
prepare-commit-msg
This hook is invoked by git commit right after preparing the default
log message, and before the editor is started.
It takes one to three parameters. The first is the name of the file
that contains the commit log message. The second is the source of the
commit message, and can be: message (if a -m or -F option was given);
template (if a -t option was given or the configuration option com-
mit.template is set); merge (if the commit is a merge or a
.git/MERGE_MSG file exists); squash (if a .git/SQUASH_MSG file exists);
or commit, followed by a commit SHA1 (if a -c, -C or \--amend option
was given).
If the exit status is non-zero, git commit will abort.
The purpose of the hook is to edit the message file in place, and it is
not suppressed by the \--no-verify option. A non-zero exit means a
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failure of the hook and aborts the commit. It should not be used as
replacement for pre-commit hook.
The sample prepare-commit-msg hook that comes with git comments out the
Conflicts: part of a merge’s commit message.
commit-msg
This hook is invoked by git commit, and can be bypassed with \--no-ver-
ify option. It takes a single parameter, the name of the file that
holds the proposed commit log message. Exiting with non-zero status
causes the git commit to abort.
The hook is allowed to edit the message file in place, and can be used
to normalize the message into some project standard format (if the pro-
ject has one). It can also be used to refuse the commit after inspect-
ing the message file.
The default commit-msg hook, when enabled, detects duplicate
"Signed-off-by" lines, and aborts the commit if one is found.
post-commit
This hook is invoked by git commit. It takes no parameter, and is
invoked after a commit is made.
This hook is meant primarily for notification, and cannot affect the
outcome of git commit.
pre-rebase
This hook is called by git rebase and can be used to prevent a branch
from getting rebased.
post-checkout
This hook is invoked when a git checkout is run after having updated
the worktree. The hook is given three parameters: the ref of the previ-
ous HEAD, the ref of the new HEAD (which may or may not have changed),
and a flag indicating whether the checkout was a branch checkout
(changing branches, flag=1) or a file checkout (retrieving a file from
the index, flag=0). This hook cannot affect the outcome of git check-
out.
It is also run after git clone, unless the --no-checkout (-n) option is
used. The first parameter given to the hook is the null-ref, the second
the ref of the new HEAD and the flag is always 1.
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This hook can be used to perform repository validity checks, auto-dis-
play differences from the previous HEAD if different, or set working
dir metadata properties.
post-merge
This hook is invoked by git merge, which happens when a git pull is
done on a local repository. The hook takes a single parameter, a status
flag specifying whether or not the merge being done was a squash merge.
This hook cannot affect the outcome of git merge and is not executed,
if the merge failed due to conflicts.
This hook can be used in conjunction with a corresponding pre-commit
hook to save and restore any form of metadata associated with the work-
ing tree (eg: permissions/ownership, ACLS, etc). See contrib/hooks/set-
gitperms.perl for an example of how to do this.
pre-receive
This hook is invoked by git-receive-pack on the remote repository,
which happens when a git push is done on a local repository. Just
before starting to update refs on the remote repository, the
pre-receive hook is invoked. Its exit status determines the success or
failure of the update.
This hook executes once for the receive operation. It takes no argu-
ments, but for each ref to be updated it receives on standard input a
line of the format:
<old-value> SP <new-value> SP <ref-name> LF
where <old-value> is the old object name stored in the ref, <new-value>
is the new object name to be stored in the ref and <ref-name> is the
full name of the ref. When creating a new ref, <old-value> is 40 0.
If the hook exits with non-zero status, none of the refs will be
updated. If the hook exits with zero, updating of individual refs can
still be prevented by the update hook.
Both standard output and standard error output are forwarded to git
send-pack on the other end, so you can simply echo messages for the
user.
update
This hook is invoked by git-receive-pack on the remote repository,
which happens when a git push is done on a local repository. Just
before updating the ref on the remote repository, the update hook is
invoked. Its exit status determines the success or failure of the ref
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update.
The hook executes once for each ref to be updated, and takes three
parameters:
o the name of the ref being updated,
o the old object name stored in the ref,
o and the new objectname to be stored in the ref.
A zero exit from the update hook allows the ref to be updated. Exiting
with a non-zero status prevents git-receive-pack from updating that
ref.
This hook can be used to prevent forced update on certain refs by mak-
ing sure that the object name is a commit object that is a descendant
of the commit object named by the old object name. That is, to enforce
a "fast-forward only" policy.
It could also be used to log the old..new status. However, it does not
know the entire set of branches, so it would end up firing one e-mail
per ref when used naively, though. The post-receive hook is more suited
to that.
Another use suggested on the mailing list is to use this hook to imple-
ment access control which is finer grained than the one based on
filesystem group.
Both standard output and standard error output are forwarded to git
send-pack on the other end, so you can simply echo messages for the
user.
The default update hook, when enabled--and with hooks.allowunannotated
config option unset or set to false--prevents unannotated tags to be
pushed.
post-receive
This hook is invoked by git-receive-pack on the remote repository,
which happens when a git push is done on a local repository. It exe-
cutes on the remote repository once after all the refs have been
updated.
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This hook executes once for the receive operation. It takes no argu-
ments, but gets the same information as the pre-receive hook does on
its standard input.
This hook does not affect the outcome of git-receive-pack, as it is
called after the real work is done.
This supersedes the post-update hook in that it gets both old and new
values of all the refs in addition to their names.
Both standard output and standard error output are forwarded to git
send-pack on the other end, so you can simply echo messages for the
user.
The default post-receive hook is empty, but there is a sample script
post-receive-email provided in the contrib/hooks directory in git dis-
tribution, which implements sending commit emails.
post-update
This hook is invoked by git-receive-pack on the remote repository,
which happens when a git push is done on a local repository. It exe-
cutes on the remote repository once after all the refs have been
updated.
It takes a variable number of parameters, each of which is the name of
ref that was actually updated.
This hook is meant primarily for notification, and cannot affect the
outcome of git-receive-pack.
The post-update hook can tell what are the heads that were pushed, but
it does not know what their original and updated values are, so it is a
poor place to do log old..new. The post-receive hook does get both
original and updated values of the refs. You might consider it instead
if you need them.
When enabled, the default post-update hook runs git update-server-info
to keep the information used by dumb transports (e.g., HTTP)
up-to-date. If you are publishing a git repository that is accessible
via HTTP, you should probably enable this hook.
Both standard output and standard error output are forwarded to git
send-pack on the other end, so you can simply echo messages for the
user.
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pre-auto-gc
This hook is invoked by git gc --auto. It takes no parameter, and exit-
ing with non-zero status from this script causes the git gc --auto to
abort.
post-rewrite
This hook is invoked by commands that rewrite commits (git commit
--amend, git-rebase; currently git-filter-branch does not call it!).
Its first argument denotes the command it was invoked by: currently one
of amend or rebase. Further command-dependent arguments may be passed
in the future.
The hook receives a list of the rewritten commits on stdin, in the for-
mat
<old-sha1> SP <new-sha1> [ SP <extra-info> ] LF
The extra-info is again command-dependent. If it is empty, the preced-
ing SP is also omitted. Currently, no commands pass any extra-info.
The hook always runs after the automatic note copying (see
"notes.rewrite.<command>" in linkgit:git-config.txt) has happened, and
thus has access to these notes.
The following command-specific comments apply:
rebase For the squash and fixup operation, all commits that were
squashed are listed as being rewritten to the squashed commit.
This means that there will be several lines sharing the same
new-sha1.
The commits are guaranteed to be listed in the order that they
were processed by rebase.
There is no default post-rewrite hook, but see the
post-receive-copy-notes script in contrib/hooks for an example
that copies your git-notes to the rewritten commits.
GIT
Part of the git(1) suite
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