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 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's commit message.
+
commit-msg
----------
This hook is meant primarily for notification, and cannot affect
the outcome of `git-commit`.
+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 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 get's
+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.
+
+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.