-Hooks used by GIT
+Hooks used by git
=================
-v0.99.6, Sep 2005
Hooks are little scripts you can place in `$GIT_DIR/hooks`
directory to trigger action at certain points. When
-`git-init-db` is run, a handful example hooks are copied in the
+`git-init` is run, a handful example hooks are copied in the
`hooks` directory of the new repository, but by default they are
-all disabled. To enable a hook, make it executable with `chmod
-+x`.
+all disabled. To enable a hook, make it executable with `chmod +x`.
This document describes the currently defined hooks.
applypatch-msg
--------------
-This hook is invoked by `git-applypatch` script, which is
-typically invoked by `git-applymbox`. It takes a single
+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 the
-'git-applypatch' to abort before applying the patch.
+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.
+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-applypatch` script, which is
-typically invoked by `git-applymbox`. It takes no parameter,
+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. Exiting with non-zero status causes the working tree
after application of the patch not committed.
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.
+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-applypatch` script, which is
-typically invoked by `git-applymbox`. It takes no parameter,
+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-applypatch`.
+the outcome of `git-am`.
pre-commit
----------
-This hook is invoked by `git-commit-script`, and can be bypassed
-with `--no-verify` option. It takes no parameter, and is
+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-script` to abort.
+causes the `git-commit` to abort.
-The default pre-commit hook, when enabled, catches introduction
+The default 'pre-commit' hook, when enabled, catches introduction
of lines with trailing whitespaces and aborts the commit when
-a such line is found.
+such a line is found.
commit-msg
----------
-This hook is invoked by `git-commit-script`, and can be bypassed
-with `--no-verify` option. It takes a single parameter, the
+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-script` to
+Exiting with non-zero status causes the `git-commit` to
abort.
The hook is allowed to edit the message file in place, and can
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 when one is found.
+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-script`. It takes no
+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-script`.
+the outcome of `git-commit`.
-The default post-commit hook, when enabled, demonstrates how to
-send out a commit notification e-mail.
+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`.
+
+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`.
+
+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]]
+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,'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]]
update
------
-This hook is invoked by `git-receive-pack`, which is invoked
-when a `git push` is done against the repository. It takes
-three parameters, name of the ref being updated, old object name
-stored in the ref, and the new objectname to be stored in the
-ref. Exiting with non-zero status from this hook prevents
-`git-receive-pack` from updating the ref.
+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:
-This can be used to prevent 'forced' update on certain refs by
+ - the name of the ref being updated,
+ - the old object name stored in the ref,
+ - 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,'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 turned on--prevents
+unannotated tags to be pushed.
+
+[[post-receive]]
+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,'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,'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]]
post-update
-----------
-This hook is invoked by `git-receive-pack`, which is invoked
-when a `git push` is done against the repository. It takes
-variable number of parameters; each of which is the name of ref
-that was actually updated.
+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 default post-update hook, when enabled, runs
+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,'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
-transport up-to-date.
+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.