NAME | SYNOPSIS | DESCRIPTION | HOOKS | GIT | COLOPHON

GITHOOKS(5)                      Git Manual                      GITHOOKS(5)

NAME         top

       githooks - Hooks used by Git

SYNOPSIS         top

       $GIT_DIR/hooks/* (or `git config core.hooksPath`/*)

DESCRIPTION         top

       Hooks are programs you can place in a hooks directory to trigger
       actions at certain points in git’s execution. Hooks that don’t have
       the executable bit set are ignored.

       By default the hooks directory is $GIT_DIR/hooks, but that can be
       changed via the core.hooksPath configuration variable (see
       git-config(1)).

       Before Git invokes a hook, it changes its working directory to either
       the root of the working tree in a non-bare repository, or to the
       $GIT_DIR in a bare repository.

       Hooks can get their arguments via the environment, command-line
       arguments, and stdin. See the documentation for each hook below for
       details.

       git init may copy hooks to the new repository, depending on its
       configuration. See the "TEMPLATE DIRECTORY" section in git-init(1)
       for details. When the rest of this document refers to "default hooks"
       it’s talking about the default template shipped with Git.

       The currently supported hooks are described below.

HOOKS         top

   applypatch-msg
       This hook is invoked by git am. It takes a single parameter, the name
       of the file that holds the proposed commit log message. Exiting with
       a 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. 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 the
       --no-verify option. It takes no parameters, and is invoked before
       obtaining the proposed commit log message and making a commit.
       Exiting with a non-zero status from this script causes the git commit
       command to abort before creating a commit.

       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 SHA-1 (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’s commit message.

   commit-msg
       This hook is invoked by git commit, and can be bypassed with the
       --no-verify option. It takes a single parameter, the name of the file
       that holds the proposed commit log message. Exiting with a 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. 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 parameters, 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. The hook may be called with one or two
       parameters. The first parameter is the upstream from which the series
       was forked. The second parameter is the branch being rebased, and is
       not set when rebasing the current branch.

   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 (e.g.: permissions/ownership, ACLS, etc). See
       contrib/hooks/setgitperms.perl for an example of how to do this.

   pre-push
       This hook is called by git push and can be used to prevent a push
       from taking place. The hook is called with two parameters which
       provide the name and location of the destination remote, if a named
       remote is not being used both values will be the same.

       Information about what is to be pushed is provided on the hook’s
       standard input with lines of the form:

           <local ref> SP <local sha1> SP <remote ref> SP <remote sha1> LF

       For instance, if the command git push origin master:foreign were run
       the hook would receive a line like the following:

           refs/heads/master 67890 refs/heads/foreign 12345

       although the full, 40-character SHA-1s would be supplied. If the
       foreign ref does not yet exist the <remote SHA-1> will be 40 0. If a
       ref is to be deleted, the <local ref> will be supplied as (delete)
       and the <local SHA-1> will be 40 0. If the local commit was specified
       by something other than a name which could be expanded (such as
       HEAD~, or a SHA-1) it will be supplied as it was originally given.

       If this hook exits with a non-zero status, git push will abort
       without pushing anything. Information about why the push is rejected
       may be sent to the user by writing to standard error.

   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.

       The number of push options given on the command line of git push
       --push-option=... can be read from the environment variable
       GIT_PUSH_OPTION_COUNT, and the options themselves are found in
       GIT_PUSH_OPTION_0, GIT_PUSH_OPTION_1,... If it is negotiated to not
       use the push options phase, the environment variables will not be
       set. If the client selects to use push options, but doesn’t transmit
       any, the count variable will be set to zero, GIT_PUSH_OPTION_COUNT=0.

   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:

       ·   the name of the ref being updated,

       ·   the old object name stored in the ref,

       ·   and the new object name 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.

       In an environment that restricts the users' access only to git
       commands over the wire, this hook can be used to implement access
       control without relying on filesystem ownership and group membership.
       See git-shell(1) for how you might use the login shell to restrict
       the user’s access to only git commands.

       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.

       The number of push options given on the command line of git push
       --push-option=... can be read from the environment variable
       GIT_PUSH_OPTION_COUNT, and the options themselves are found in
       GIT_PUSH_OPTION_0, GIT_PUSH_OPTION_1,... If it is negotiated to not
       use the push options phase, the environment variables will not be
       set. If the client selects to use push options, but doesn’t transmit
       any, the count variable will be set to zero, GIT_PUSH_OPTION_COUNT=0.

   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.

   push-to-checkout
       This hook is invoked by git-receive-pack on the remote repository,
       which happens when a git push is done on a local repository, when the
       push tries to update the branch that is currently checked out and the
       receive.denyCurrentBranch configuration variable is set to
       updateInstead. Such a push by default is refused if the working tree
       and the index of the remote repository has any difference from the
       currently checked out commit; when both the working tree and the
       index match the current commit, they are updated to match the newly
       pushed tip of the branch. This hook is to be used to override the
       default behaviour.

       The hook receives the commit with which the tip of the current branch
       is going to be updated. It can exit with a non-zero status to refuse
       the push (when it does so, it must not modify the index or the
       working tree). Or it can make any necessary changes to the working
       tree and to the index to bring them to the desired state when the tip
       of the current branch is updated to the new commit, and exit with a
       zero status.

       For example, the hook can simply run git read-tree -u -m HEAD "$1" in
       order to emulate git fetch that is run in the reverse direction with
       git push, as the two-tree form of read-tree -u -m is essentially the
       same as git checkout that switches branches while keeping the local
       changes in the working tree that do not interfere with the difference
       between the branches.

   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 git-config(1)) 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         top

       Part of the git(1) suite

COLOPHON         top

       This page is part of the git (Git distributed version control system)
       project.  Information about the project can be found at 
       ⟨http://git-scm.com/⟩.  If you have a bug report for this manual page,
       see ⟨http://git-scm.com/community⟩.  This page was obtained from the
       project's upstream Git repository ⟨https://github.com/git/git.git⟩ on
       2017-03-13.  If you discover any rendering problems in this HTML ver‐
       sion of the page, or you believe there is a better or more up-to-date
       source for the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original man‐
       ual page), send a mail to man-pages@man7.org

Git 2.9.2.574.gc6b0597           08/07/2016                      GITHOOKS(5)