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<!DOCTYPE sect2 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">\r
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<sect2 lang="en" id="githooks(5)">\r
    <title>githooks(5)</title>\r
<indexterm>\r
<primary>githooks(5)</primary>\r
</indexterm>\r
<simplesect id="githooks(5)__name">\r
<title>NAME</title>\r
<simpara>githooks - Hooks used by Git</simpara>\r
</simplesect>\r
<simplesect id="githooks(5)__synopsis">\r
<title>SYNOPSIS</title>\r
<simpara>$GIT_DIR/hooks/*</simpara>\r
</simplesect>\r
<simplesect id="githooks(5)__description">\r
<title>DESCRIPTION</title>\r
<simpara>Hooks are little scripts you can place in <emphasis>$GIT_DIR/hooks</emphasis>\r
directory to trigger action at certain points.  When\r
<emphasis>git init</emphasis> is run, a handful of example hooks are copied into the\r
<emphasis>hooks</emphasis> directory of the new repository, but by default they are\r
all disabled.  To enable a hook, rename it by removing its <emphasis>.sample</emphasis>\r
suffix.</simpara>\r
<note><simpara>It is also a requirement for a given hook to be executable.\r
However - in a freshly initialized repository - the <emphasis>.sample</emphasis> files are\r
executable by default.</simpara></note>\r
<simpara>This document describes the currently defined hooks.</simpara>\r
</simplesect>\r
<simplesect id="githooks(5)__hooks">\r
<title>HOOKS</title>\r
<section id="githooks(5)__applypatch_msg">\r
<title>applypatch-msg</title>\r
<simpara>This hook is invoked by <emphasis>git am</emphasis> script.  It takes a single\r
parameter, the name of the file that holds the proposed commit\r
log message.  Exiting with non-zero status causes\r
<emphasis>git am</emphasis> to abort before applying the patch.</simpara>\r
<simpara>The hook is allowed to edit the message file in place, and can\r
be used to normalize the message into some project standard\r
format (if the project has one). It can also be used to refuse\r
the commit after inspecting the message file.</simpara>\r
<simpara>The default <emphasis>applypatch-msg</emphasis> hook, when enabled, runs the\r
<emphasis>commit-msg</emphasis> hook, if the latter is enabled.</simpara>\r
</section>\r
<section id="githooks(5)__pre_applypatch">\r
<title>pre-applypatch</title>\r
<simpara>This hook is invoked by <emphasis>git am</emphasis>.  It takes no parameter, and is\r
invoked after the patch is applied, but before a commit is made.</simpara>\r
<simpara>If it exits with non-zero status, then the working tree will not be\r
committed after applying the patch.</simpara>\r
<simpara>It can be used to inspect the current working tree and refuse to\r
make a commit if it does not pass certain test.</simpara>\r
<simpara>The default <emphasis>pre-applypatch</emphasis> hook, when enabled, runs the\r
<emphasis>pre-commit</emphasis> hook, if the latter is enabled.</simpara>\r
</section>\r
<section id="githooks(5)__post_applypatch">\r
<title>post-applypatch</title>\r
<simpara>This hook is invoked by <emphasis>git am</emphasis>.  It takes no parameter,\r
and is invoked after the patch is applied and a commit is made.</simpara>\r
<simpara>This hook is meant primarily for notification, and cannot affect\r
the outcome of <emphasis>git am</emphasis>.</simpara>\r
</section>\r
<section id="githooks(5)__pre_commit">\r
<title>pre-commit</title>\r
<simpara>This hook is invoked by <emphasis>git commit</emphasis>, and can be bypassed\r
with <emphasis>--no-verify</emphasis> option.  It takes no parameter, and is\r
invoked before obtaining the proposed commit log message and\r
making a commit.  Exiting with non-zero status from this script\r
causes the <emphasis>git commit</emphasis> to abort.</simpara>\r
<simpara>The default <emphasis>pre-commit</emphasis> hook, when enabled, catches introduction\r
of lines with trailing whitespaces and aborts the commit when\r
such a line is found.</simpara>\r
<simpara>All the <emphasis>git commit</emphasis> hooks are invoked with the environment\r
variable <emphasis>GIT_EDITOR=:</emphasis> if the command will not bring up an editor\r
to modify the commit message.</simpara>\r
</section>\r
<section id="githooks(5)__prepare_commit_msg">\r
<title>prepare-commit-msg</title>\r
<simpara>This hook is invoked by <emphasis>git commit</emphasis> right after preparing the\r
default log message, and before the editor is started.</simpara>\r
<simpara>It takes one to three parameters.  The first is the name of the file\r
that contains the commit log message.  The second is the source of the commit\r
message, and can be: <emphasis>message</emphasis> (if a <emphasis>-m</emphasis> or <emphasis>-F</emphasis> option was\r
given); <emphasis>template</emphasis> (if a <emphasis>-t</emphasis> option was given or the\r
configuration option <emphasis>commit.template</emphasis> is set); <emphasis>merge</emphasis> (if the\r
commit is a merge or a <emphasis>.git/MERGE_MSG</emphasis> file exists); <emphasis>squash</emphasis>\r
(if a <emphasis>.git/SQUASH_MSG</emphasis> file exists); or <emphasis>commit</emphasis>, followed by\r
a commit SHA-1 (if a <emphasis>-c</emphasis>, <emphasis>-C</emphasis> or <emphasis>--amend</emphasis> option was given).</simpara>\r
<simpara>If the exit status is non-zero, <emphasis>git commit</emphasis> will abort.</simpara>\r
<simpara>The purpose of the hook is to edit the message file in place, and\r
it is not suppressed by the <emphasis>--no-verify</emphasis> option.  A non-zero exit\r
means a failure of the hook and aborts the commit.  It should not\r
be used as replacement for pre-commit hook.</simpara>\r
<simpara>The sample <emphasis>prepare-commit-msg</emphasis> hook that comes with Git comments\r
out the <emphasis>Conflicts:</emphasis> part of a merge's commit message.</simpara>\r
</section>\r
<section id="githooks(5)__commit_msg">\r
<title>commit-msg</title>\r
<simpara>This hook is invoked by <emphasis>git commit</emphasis>, and can be bypassed\r
with <emphasis>--no-verify</emphasis> option.  It takes a single parameter, the\r
name of the file that holds the proposed commit log message.\r
Exiting with non-zero status causes the <emphasis>git commit</emphasis> to\r
abort.</simpara>\r
<simpara>The hook is allowed to edit the message file in place, and can\r
be used to normalize the message into some project standard\r
format (if the project has one). It can also be used to refuse\r
the commit after inspecting the message file.</simpara>\r
<simpara>The default <emphasis>commit-msg</emphasis> hook, when enabled, detects duplicate\r
"Signed-off-by" lines, and aborts the commit if one is found.</simpara>\r
</section>\r
<section id="githooks(5)__post_commit">\r
<title>post-commit</title>\r
<simpara>This hook is invoked by <emphasis>git commit</emphasis>.  It takes no\r
parameter, and is invoked after a commit is made.</simpara>\r
<simpara>This hook is meant primarily for notification, and cannot affect\r
the outcome of <emphasis>git commit</emphasis>.</simpara>\r
</section>\r
<section id="githooks(5)__pre_rebase">\r
<title>pre-rebase</title>\r
<simpara>This hook is called by <emphasis>git rebase</emphasis> and can be used to prevent a\r
branch from getting rebased.  The hook may be called with one or\r
two parameters.  The first parameter is the upstream from which\r
the series was forked.  The second parameter is the branch being\r
rebased, and is not set when rebasing the current branch.</simpara>\r
</section>\r
<section id="githooks(5)__post_checkout">\r
<title>post-checkout</title>\r
<simpara>This hook is invoked when a <emphasis>git checkout</emphasis> is run after having updated the\r
worktree.  The hook is given three parameters: the ref of the previous HEAD,\r
the ref of the new HEAD (which may or may not have changed), and a flag\r
indicating whether the checkout was a branch checkout (changing branches,\r
flag=1) or a file checkout (retrieving a file from the index, flag=0).\r
This hook cannot affect the outcome of <emphasis>git checkout</emphasis>.</simpara>\r
<simpara>It is also run after <emphasis>git clone</emphasis>, unless the --no-checkout (-n) option is\r
used. The first parameter given to the hook is the null-ref, the second the\r
ref of the new HEAD and the flag is always 1.</simpara>\r
<simpara>This hook can be used to perform repository validity checks, auto-display\r
differences from the previous HEAD if different, or set working dir metadata\r
properties.</simpara>\r
</section>\r
<section id="githooks(5)__post_merge">\r
<title>post-merge</title>\r
<simpara>This hook is invoked by <emphasis>git merge</emphasis>, which happens when a <emphasis>git pull</emphasis>\r
is done on a local repository.  The hook takes a single parameter, a status\r
flag specifying whether or not the merge being done was a squash merge.\r
This hook cannot affect the outcome of <emphasis>git merge</emphasis> and is not executed,\r
if the merge failed due to conflicts.</simpara>\r
<simpara>This hook can be used in conjunction with a corresponding pre-commit hook to\r
save and restore any form of metadata associated with the working tree\r
(e.g.: permissions/ownership, ACLS, etc).  See contrib/hooks/setgitperms.perl\r
for an example of how to do this.</simpara>\r
</section>\r
<section id="githooks(5)__pre_push">\r
<title>pre-push</title>\r
<simpara>This hook is called by <emphasis>git push</emphasis> and can be used to prevent a push from taking\r
place.  The hook is called with two parameters which provide the name and\r
location of the destination remote, if a named remote is not being used both\r
values will be the same.</simpara>\r
<simpara>Information about what is to be pushed is provided on the hook's standard\r
input with lines of the form:</simpara>\r
<literallayout class="monospaced">&lt;local ref&gt; SP &lt;local sha1&gt; SP &lt;remote ref&gt; SP &lt;remote sha1&gt; LF</literallayout>\r
<simpara>For instance, if the command <literal>git push origin master:foreign</literal> were run the\r
hook would receive a line like the following:</simpara>\r
<literallayout class="monospaced">refs/heads/master 67890 refs/heads/foreign 12345</literallayout>\r
<simpara>although the full, 40-character SHA-1s would be supplied.  If the foreign ref\r
does not yet exist the <emphasis>&lt;remote SHA-1&gt;</emphasis> will be 40 <emphasis>0</emphasis>.  If a ref is to be\r
deleted, the <emphasis>&lt;local ref&gt;</emphasis> will be supplied as <emphasis>(delete)</emphasis> and the <emphasis>&lt;local\r
SHA-1&gt;</emphasis> will be 40 <emphasis>0</emphasis>.  If the local commit was specified by something other\r
than a name which could be expanded (such as <emphasis>HEAD~</emphasis>, or a SHA-1) it will be\r
supplied as it was originally given.</simpara>\r
<simpara>If this hook exits with a non-zero status, <emphasis>git push</emphasis> will abort without\r
pushing anything.  Information about why the push is rejected may be sent\r
to the user by writing to standard error.</simpara>\r
</section>\r
<section id="githooks(5)_pre-receive">\r
<title>pre-receive</title>\r
<simpara>This hook is invoked by <emphasis>git-receive-pack</emphasis> on the remote repository,\r
which happens when a <emphasis>git push</emphasis> is done on a local repository.\r
Just before starting to update refs on the remote repository, the\r
pre-receive hook is invoked.  Its exit status determines the success\r
or failure of the update.</simpara>\r
<simpara>This hook executes once for the receive operation. It takes no\r
arguments, but for each ref to be updated it receives on standard\r
input a line of the format:</simpara>\r
<literallayout class="monospaced">&lt;old-value&gt; SP &lt;new-value&gt; SP &lt;ref-name&gt; LF</literallayout>\r
<simpara>where <emphasis>&lt;old-value&gt;</emphasis> is the old object name stored in the ref,\r
<emphasis>&lt;new-value&gt;</emphasis> is the new object name to be stored in the ref and\r
<emphasis>&lt;ref-name&gt;</emphasis> is the full name of the ref.\r
When creating a new ref, <emphasis>&lt;old-value&gt;</emphasis> is 40 <emphasis>0</emphasis>.</simpara>\r
<simpara>If the hook exits with non-zero status, none of the refs will be\r
updated. If the hook exits with zero, updating of individual refs can\r
still be prevented by the <link linkend="githooks(5)_update"><emphasis>update</emphasis></link> hook.</simpara>\r
<simpara>Both standard output and standard error output are forwarded to\r
<emphasis>git send-pack</emphasis> on the other end, so you can simply <emphasis>echo</emphasis> messages\r
for the user.</simpara>\r
</section>\r
<section id="githooks(5)_update">\r
<title>update</title>\r
<simpara>This hook is invoked by <emphasis>git-receive-pack</emphasis> on the remote repository,\r
which happens when a <emphasis>git push</emphasis> is done on a local repository.\r
Just before updating the ref on the remote repository, the update hook\r
is invoked.  Its exit status determines the success or failure of\r
the ref update.</simpara>\r
<simpara>The hook executes once for each ref to be updated, and takes\r
three parameters:</simpara>\r
<itemizedlist>\r
<listitem>\r
<simpara>\r
the name of the ref being updated,\r
</simpara>\r
</listitem>\r
<listitem>\r
<simpara>\r
the old object name stored in the ref,\r
</simpara>\r
</listitem>\r
<listitem>\r
<simpara>\r
and the new object name to be stored in the ref.\r
</simpara>\r
</listitem>\r
</itemizedlist>\r
<simpara>A zero exit from the update hook allows the ref to be updated.\r
Exiting with a non-zero status prevents <emphasis>git-receive-pack</emphasis>\r
from updating that ref.</simpara>\r
<simpara>This hook can be used to prevent <emphasis>forced</emphasis> update on certain refs by\r
making sure that the object name is a commit object that is a\r
descendant of the commit object named by the old object name.\r
That is, to enforce a "fast-forward only" policy.</simpara>\r
<simpara>It could also be used to log the old..new status.  However, it\r
does not know the entire set of branches, so it would end up\r
firing one e-mail per ref when used naively, though.  The\r
<link linkend="githooks(5)_post-receive"><emphasis>post-receive</emphasis></link> hook is more suited to that.</simpara>\r
<simpara>Another use suggested on the mailing list is to use this hook to\r
implement access control which is finer grained than the one\r
based on filesystem group.</simpara>\r
<simpara>Both standard output and standard error output are forwarded to\r
<emphasis>git send-pack</emphasis> on the other end, so you can simply <emphasis>echo</emphasis> messages\r
for the user.</simpara>\r
<simpara>The default <emphasis>update</emphasis> hook, when enabled--and with\r
<emphasis>hooks.allowunannotated</emphasis> config option unset or set to false--prevents\r
unannotated tags to be pushed.</simpara>\r
</section>\r
<section id="githooks(5)_post-receive">\r
<title>post-receive</title>\r
<simpara>This hook is invoked by <emphasis>git-receive-pack</emphasis> on the remote repository,\r
which happens when a <emphasis>git push</emphasis> is done on a local repository.\r
It executes on the remote repository once after all the refs have\r
been updated.</simpara>\r
<simpara>This hook executes once for the receive operation.  It takes no\r
arguments, but gets the same information as the\r
<link linkend="githooks(5)_pre-receive"><emphasis>pre-receive</emphasis></link>\r
hook does on its standard input.</simpara>\r
<simpara>This hook does not affect the outcome of <emphasis>git-receive-pack</emphasis>, as it\r
is called after the real work is done.</simpara>\r
<simpara>This supersedes the <link linkend="githooks(5)_post-update"><emphasis>post-update</emphasis></link> hook in that it gets\r
both old and new values of all the refs in addition to their\r
names.</simpara>\r
<simpara>Both standard output and standard error output are forwarded to\r
<emphasis>git send-pack</emphasis> on the other end, so you can simply <emphasis>echo</emphasis> messages\r
for the user.</simpara>\r
<simpara>The default <emphasis>post-receive</emphasis> hook is empty, but there is\r
a sample script <emphasis>post-receive-email</emphasis> provided in the <emphasis>contrib/hooks</emphasis>\r
directory in Git distribution, which implements sending commit\r
emails.</simpara>\r
</section>\r
<section id="githooks(5)_post-update">\r
<title>post-update</title>\r
<simpara>This hook is invoked by <emphasis>git-receive-pack</emphasis> on the remote repository,\r
which happens when a <emphasis>git push</emphasis> is done on a local repository.\r
It executes on the remote repository once after all the refs have\r
been updated.</simpara>\r
<simpara>It takes a variable number of parameters, each of which is the\r
name of ref that was actually updated.</simpara>\r
<simpara>This hook is meant primarily for notification, and cannot affect\r
the outcome of <emphasis>git-receive-pack</emphasis>.</simpara>\r
<simpara>The <emphasis>post-update</emphasis> hook can tell what are the heads that were pushed,\r
but it does not know what their original and updated values are,\r
so it is a poor place to do log old..new. The\r
<link linkend="githooks(5)_post-receive"><emphasis>post-receive</emphasis></link> hook does get both original and\r
updated values of the refs. You might consider it instead if you need\r
them.</simpara>\r
<simpara>When enabled, the default <emphasis>post-update</emphasis> hook runs\r
<emphasis>git update-server-info</emphasis> to keep the information used by dumb\r
transports (e.g., HTTP) up-to-date.  If you are publishing\r
a Git repository that is accessible via HTTP, you should\r
probably enable this hook.</simpara>\r
<simpara>Both standard output and standard error output are forwarded to\r
<emphasis>git send-pack</emphasis> on the other end, so you can simply <emphasis>echo</emphasis> messages\r
for the user.</simpara>\r
</section>\r
<section id="githooks(5)__push_to_checkout">\r
<title>push-to-checkout</title>\r
<simpara>This hook is invoked by <emphasis>git-receive-pack</emphasis> on the remote repository,\r
which happens when a <emphasis>git push</emphasis> is done on a local repository, when\r
the push tries to update the branch that is currently checked out\r
and the <emphasis>receive.denyCurrentBranch</emphasis> configuration variable is set to\r
<emphasis>updateInstead</emphasis>.  Such a push by default is refused if the working\r
tree and the index of the remote repository has any difference from\r
the currently checked out commit; when both the working tree and the\r
index match the current commit, they are updated to match the newly\r
pushed tip of the branch.  This hook is to be used to override the\r
default behaviour.</simpara>\r
<simpara>The hook receives the commit with which the tip of the current\r
branch is going to be updated.  It can exit with a non-zero status\r
to refuse the push (when it does so, it must not modify the index or\r
the working tree).  Or it can make any necessary changes to the\r
working tree and to the index to bring them to the desired state\r
when the tip of the current branch is updated to the new commit, and\r
exit with a zero status.</simpara>\r
<simpara>For example, the hook can simply run <emphasis>git read-tree -u -m HEAD "$1"</emphasis>\r
in order to emulate <emphasis>git fetch</emphasis> that is run in the reverse direction\r
with <emphasis>git push</emphasis>, as the two-tree form of <emphasis>read-tree -u -m</emphasis> is\r
essentially the same as <emphasis>git checkout</emphasis> that switches branches while\r
keeping the local changes in the working tree that do not interfere\r
with the difference between the branches.</simpara>\r
</section>\r
<section id="githooks(5)__pre_auto_gc">\r
<title>pre-auto-gc</title>\r
<simpara>This hook is invoked by <emphasis>git gc --auto</emphasis>. It takes no parameter, and\r
exiting with non-zero status from this script causes the <emphasis>git gc --auto</emphasis>\r
to abort.</simpara>\r
</section>\r
<section id="githooks(5)__post_rewrite">\r
<title>post-rewrite</title>\r
<simpara>This hook is invoked by commands that rewrite commits (<emphasis>git commit\r
--amend</emphasis>, <emphasis>git-rebase</emphasis>; currently <emphasis>git-filter-branch</emphasis> does <emphasis>not</emphasis> call\r
it!).  Its first argument denotes the command it was invoked by:\r
currently one of <emphasis>amend</emphasis> or <emphasis>rebase</emphasis>.  Further command-dependent\r
arguments may be passed in the future.</simpara>\r
<simpara>The hook receives a list of the rewritten commits on stdin, in the\r
format</simpara>\r
<literallayout class="monospaced">&lt;old-sha1&gt; SP &lt;new-sha1&gt; [ SP &lt;extra-info&gt; ] LF</literallayout>\r
<simpara>The <emphasis>extra-info</emphasis> is again command-dependent.  If it is empty, the\r
preceding SP is also omitted.  Currently, no commands pass any\r
<emphasis>extra-info</emphasis>.</simpara>\r
<simpara>The hook always runs after the automatic note copying (see\r
"notes.rewrite.&lt;command&gt;" in <xref linkend="git-config(1)" />) has happened, and\r
thus has access to these notes.</simpara>\r
<simpara>The following command-specific comments apply:</simpara>\r
<variablelist>\r
<varlistentry>\r
<term>\r
rebase\r
</term>\r
<listitem>\r
<simpara>\r
        For the <emphasis>squash</emphasis> and <emphasis>fixup</emphasis> operation, all commits that were\r
        squashed are listed as being rewritten to the squashed commit.\r
        This means that there will be several lines sharing the same\r
        <emphasis>new-sha1</emphasis>.\r
</simpara>\r
<simpara>The commits are guaranteed to be listed in the order that they were\r
processed by rebase.</simpara>\r
</listitem>\r
</varlistentry>\r
</variablelist>\r
</section>\r
</simplesect>\r
<simplesect id="githooks(5)__git">\r
<title>GIT</title>\r
<simpara>Part of the <xref linkend="git(1)" /> suite</simpara>\r
</simplesect>\r
</sect2>\r