githooks(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | HOOKS | GIT | NOTES | 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
       $GIT_DIR in a bare repository or the root of the working tree in a
       non-bare repository. An exception are hooks triggered during a push
       (pre-receive, update, post-receive, post-update, push-to-checkout)
       which are always executed in $GIT_DIR.

       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(1). 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(1). 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(1). 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(1), 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.

       The default pre-commit hook, when enabled—and with the
       hooks.allownonascii config option unset or set to false—prevents the
       use of non-ASCII filenames.

   pre-merge-commit
       This hook is invoked by git-merge(1), and can be bypassed with the
       --no-verify option. It takes no parameters, and is invoked after the
       merge has been carried out successfully and before obtaining the
       proposed commit log message to make a commit. Exiting with a non-zero
       status from this script causes the git merge command to abort before
       creating a commit.

       The default pre-merge-commit hook, when enabled, runs the pre-commit
       hook, if the latter is enabled.

       This hook is invoked with the environment variable GIT_EDITOR=: if
       the command will not bring up an editor to modify the commit message.

       If the merge cannot be carried out automatically, the conflicts need
       to be resolved and the result committed separately (see
       git-merge(1)). At that point, this hook will not be executed, but the
       pre-commit hook will, if it is enabled.

   prepare-commit-msg
       This hook is invoked by git-commit(1) 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 removes the
       help message found in the commented portion of the commit template.

   commit-msg
       This hook is invoked by git-commit(1) and git-merge(1), 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 command 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(1). 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(1) 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(1) or git-switch(1) 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 switch or git checkout.

       It is also run after git-clone(1), 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. Likewise for git worktree add unless --no-checkout is used.

       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(1), 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(1) 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(1) when it reacts to git
       push and updates reference(s) in its 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.

       See the section on "Quarantine Environment" in git-receive-pack(1)
       for some caveats.

   update
       This hook is invoked by git-receive-pack(1) when it reacts to git
       push and updates reference(s) in its 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(1) when it reacts to git
       push and updates reference(s) in its 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(1) when it reacts to git
       push and updates reference(s) in its 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.

   reference-transaction
       This hook is invoked by any Git command that performs reference
       updates. It executes whenever a reference transaction is prepared,
       committed or aborted and may thus get called multiple times.

       The hook takes exactly one argument, which is the current state the
       given reference transaction is in:

       ·   "prepared": All reference updates have been queued to the
           transaction and references were locked on disk.

       ·   "committed": The reference transaction was committed and all
           references now have their respective new value.

       ·   "aborted": The reference transaction was aborted, no changes were
           performed and the locks have been released.

       For each reference update that was added to the transaction, the hook
       receives on standard input a line of the format:

           <old-value> SP <new-value> SP <ref-name> LF

       The exit status of the hook is ignored for any state except for the
       "prepared" state. In the "prepared" state, a non-zero exit status
       will cause the transaction to be aborted. The hook will not be called
       with "aborted" state in that case.

   push-to-checkout
       This hook is invoked by git-receive-pack(1) when it reacts to git
       push and updates reference(s) in its repository, and 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 git read-tree -u -m is essentially
       the same as git switch or 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 (see git-gc(1)). 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(1)
       when called with --amend and git-rebase(1); however, full-history
       (re)writing tools like git-fast-import(1) or git-filter-repo[1]
       typically do 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.

   sendemail-validate
       This hook is invoked by git-send-email(1). It takes a single
       parameter, the name of the file that holds the e-mail to be sent.
       Exiting with a non-zero status causes git send-email to abort before
       sending any e-mails.

   fsmonitor-watchman
       This hook is invoked when the configuration option core.fsmonitor is
       set to .git/hooks/fsmonitor-watchman or
       .git/hooks/fsmonitor-watchmanv2 depending on the version of the hook
       to use.

       Version 1 takes two arguments, a version (1) and the time in elapsed
       nanoseconds since midnight, January 1, 1970.

       Version 2 takes two arguments, a version (2) and a token that is used
       for identifying changes since the token. For watchman this would be a
       clock id. This version must output to stdout the new token followed
       by a NUL before the list of files.

       The hook should output to stdout the list of all files in the working
       directory that may have changed since the requested time. The logic
       should be inclusive so that it does not miss any potential changes.
       The paths should be relative to the root of the working directory and
       be separated by a single NUL.

       It is OK to include files which have not actually changed. All
       changes including newly-created and deleted files should be included.
       When files are renamed, both the old and the new name should be
       included.

       Git will limit what files it checks for changes as well as which
       directories are checked for untracked files based on the path names
       given.

       An optimized way to tell git "all files have changed" is to return
       the filename /.

       The exit status determines whether git will use the data from the
       hook to limit its search. On error, it will fall back to verifying
       all files and folders.

   p4-changelist
       This hook is invoked by git-p4 submit.

       The p4-changelist hook is executed after the changelist message has
       been edited by the user. It can be bypassed with the --no-verify
       option. It takes a single parameter, the name of the file that holds
       the proposed changelist text. Exiting with a non-zero status causes
       the command to abort.

       The hook is allowed to edit the changelist file and can be used to
       normalize the text into some project standard format. It can also be
       used to refuse the Submit after inspect the message file.

       Run git-p4 submit --help for details.

   p4-prepare-changelist
       This hook is invoked by git-p4 submit.

       The p4-prepare-changelist hook is executed right after preparing the
       default changelist message and before the editor is started. It takes
       one parameter, the name of the file that contains the changelist
       text. Exiting with a non-zero status from the script will abort the
       process.

       The purpose of the hook is to edit the message file in place, and it
       is not supressed by the --no-verify option. This hook is called even
       if --prepare-p4-only is set.

       Run git-p4 submit --help for details.

   p4-post-changelist
       This hook is invoked by git-p4 submit.

       The p4-post-changelist hook is invoked after the submit has
       successfully occured in P4. It takes no parameters and is meant
       primarily for notification and cannot affect the outcome of the git
       p4 submit action.

       Run git-p4 submit --help for details.

   p4-pre-submit
       This hook is invoked by git-p4 submit. It takes no parameters and
       nothing from standard input. Exiting with non-zero status from this
       script prevent git-p4 submit from launching. It can be bypassed with
       the --no-verify command line option. Run git-p4 submit --help for
       details.

   post-index-change
       This hook is invoked when the index is written in read-cache.c
       do_write_locked_index.

       The first parameter passed to the hook is the indicator for the
       working directory being updated. "1" meaning working directory was
       updated or "0" when the working directory was not updated.

       The second parameter passed to the hook is the indicator for whether
       or not the index was updated and the skip-worktree bit could have
       changed. "1" meaning skip-worktree bits could have been updated and
       "0" meaning they were not.

       Only one parameter should be set to "1" when the hook runs. The hook
       running passing "1", "1" should not be possible.

GIT top

       Part of the git(1) suite

NOTES top

        1. git-filter-repo
           https://github.com/newren/git-filter-repo

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
       2020-08-13.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-08-11.)  If you discover any
       rendering problems in this HTML version 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 manual page), send a mail to
       man-pages@man7.org

Git 2.28.0.202.g7814e8           08/12/2020                      GITHOOKS(5)

Pages that refer to this page: git(1) , git-am(1) , git-commit(1) , git-config(1) , git-gc(1) , git-init(1) , git-merge(1) , git-pull(1) , git-push(1) , git-rebase(1) , git-send-email(1) , git-send-pack(1) , git-update-index(1) , gitrepository-layout(5) , gitcvs-migration(7)