GITHOOKS(5)                                                        GITHOOKS(5)



NAME
       githooks - 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
       repository, 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.
              However - 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
       project has one). It can also be used to refuse the commit after
       inspecting 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.


       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-verify 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
       commit.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
       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&#8217;s commit message.


   commit-msg
       This hook is invoked by git commit, and can be bypassed with
       --no-verify 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
       project has one). It can also be used to refuse the commit after
       inspecting 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
       previous 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 checkout.


       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.


       This hook can be used to perform repository validity checks,
       auto-display 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
       working tree (eg: permissions/ownership, ACLS, etc). See
       contrib/hooks/setgitperms.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
       arguments, 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
       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
       making 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
       implement 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
       executes on the remote repository once after all the refs have been
       updated.


       This hook executes once for the receive operation. It takes no
       arguments, 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
       distribution, 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
       executes 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.


   pre-auto-gc
       This hook is invoked by git gc --auto. It takes no parameter, and
       exiting 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
       format

       <old-sha1> SP <new-sha1> [ SP <extra-info> ] LF


       The extra-info is again command-dependent. If it is empty, the
       preceding 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.


GIT
       Part of the git(1) suite




                                                                   GITHOOKS(5)
