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
       object name (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 trailers, 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, other than that the hook’s exit status becomes the exit
       status of these two commands.

       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 object name> SP <remote ref> SP <remote object name> 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 object name would be supplied. If the foreign
       ref does not yet exist the <remote object name> will be the
       all-zeroes object name. If a ref is to be deleted, the <local
       ref> will be supplied as (delete) and the <local object name>
       will be the all-zeroes object name. If the local commit was
       specified by something other than a name which could be expanded
       (such as HEAD~, or an object name) 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 the all-zeroes object name.

       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.

   proc-receive
       This hook is invoked by git-receive-pack(1). If the server has
       set the multi-valued config variable receive.procReceiveRefs, and
       the commands sent to receive-pack have matching reference names,
       these commands will be executed by this hook, instead of by the
       internal execute_commands() function. This hook is responsible
       for updating the relevant references and reporting the results
       back to receive-pack.

       This hook executes once for the receive operation. It takes no
       arguments, but uses a pkt-line format protocol to communicate
       with receive-pack to read commands, push-options and send
       results. In the following example for the protocol, the letter S
       stands for receive-pack and the letter H stands for this hook.

           # Version and features negotiation.
           S: PKT-LINE(version=1\0push-options atomic...)
           S: flush-pkt
           H: PKT-LINE(version=1\0push-options...)
           H: flush-pkt

           # Send commands from server to the hook.
           S: PKT-LINE(<old-oid> <new-oid> <ref>)
           S: ... ...
           S: flush-pkt
           # Send push-options only if the 'push-options' feature is enabled.
           S: PKT-LINE(push-option)
           S: ... ...
           S: flush-pkt

           # Receive result from the hook.
           # OK, run this command successfully.
           H: PKT-LINE(ok <ref>)
           # NO, I reject it.
           H: PKT-LINE(ng <ref> <reason>)
           # Fall through, let 'receive-pack' to execute it.
           H: PKT-LINE(ok <ref>)
           H: PKT-LINE(option fall-through)
           # OK, but has an alternate reference.  The alternate reference name
           # and other status can be given in option directives.
           H: PKT-LINE(ok <ref>)
           H: PKT-LINE(option refname <refname>)
           H: PKT-LINE(option old-oid <old-oid>)
           H: PKT-LINE(option new-oid <new-oid>)
           H: PKT-LINE(option forced-update)
           H: ... ...
           H: flush-pkt

       Each command for the proc-receive hook may point to a
       pseudo-reference and always has a zero-old as its old-oid, while
       the proc-receive hook may update an alternate reference and the
       alternate reference may exist already with a non-zero old-oid.
       For this case, this hook will use "option" directives to report
       extended attributes for the reference given by the leading "ok"
       directive.

       The report of the commands of this hook should have the same
       order as the input. The exit status of the proc-receive hook only
       determines the success or failure of the group of commands sent
       to it, unless atomic push is in use.

   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 does not cover symbolic references (but that may
       change in the future).

       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

       where <old-value> is the old object name passed into the
       reference transaction, <new-value> is the new object name to be
       stored in the ref and <ref-name> is the full name of the ref.
       When force updating the reference regardless of its current value
       or when the reference is to be created anew, <old-value> is the
       all-zeroes object name. To distinguish these cases, you can
       inspect the current value of <ref-name> via git rev-parse.

       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-object-name> SP <new-object-name> [ 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-object-name.

           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 suppressed 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 occurred 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 2021-06-20.  (At that time,
       the date of the most recent commit that was found in the
       repository was 2021-06-14.)  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 2.32.0.93.g670b81a         06/17/2021                    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)