Updated documentation of hooks in git-receive-pack.

Added documentation of pre-receive and post-receive hooks and updated
documentation of update and post-update hooks.

[jc: with minor copy-editing]

Signed-off-by: Jan Hudec <bulb@ucw.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Documentation/hooks.txt b/Documentation/hooks.txt
index b083290d120b36e882c2a6d190e58ae1ee07b02f..80ba6709ad8759ec6f3f8ed63b804ff6a901c111 100644 (file)
--- a/Documentation/hooks.txt
+++ b/Documentation/hooks.txt
@@ -90,6 +90,35 @@ parameter, and is invoked after a commit is made.
 This hook is meant primarily for notification, and cannot affect
 the outcome of `git-commit`.
 
 This hook is meant primarily for notification, and cannot affect
 the outcome of `git-commit`.
 

+[[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.
+
+If you want to report something to the `git-send-pack` on the other end,
+you can simply `echo` your messages.
+
+[[update]]

 update
 ------
 
 update
 ------
 


@@ -108,7 +137,7 @@ three parameters:
 
 A zero exit from the update hook allows the ref to be updated.
 Exiting with a non-zero status prevents `git-receive-pack`
 
 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 the ref.
+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
 
 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


@@ -117,7 +146,8 @@ 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
 
 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.
+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
 
 Another use suggested on the mailing list is to use this hook to
 implement access control which is finer grained than the one


@@ -127,9 +157,38 @@ The standard output of this hook is sent to `stderr`, so if you
 want to report something to the `git-send-pack` on the other end,
 you can simply `echo` your messages.
 
 want to report something to the `git-send-pack` on the other end,
 you can simply `echo` your messages.
 

-The default 'update' hook, when enabled, demonstrates how to
-send out a notification e-mail.
+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`
+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 actually get's
+both old and new values of all the refs.
+
+If you want to report something to the `git-send-pack` on the
+other end, you can simply `echo` your messages.
+
+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
 -----------
 
 post-update
 -----------
 


@@ -148,12 +207,16 @@ 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.
 
 but it does not know what their original and updated values are,
 so it is a poor place to do log old..new.
 

+In general, `post-receive` hook is preferred when the hook needs
+to decide its acion on the status of the entire set of refs
+being updated, as this hook is called once per ref, with
+information only on a single ref at a time.
+

 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.
 
 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.
 

-The standard output of this hook is sent to `/dev/null`; if you
-want to report something to the `git-send-pack` on the other end,
-you can redirect your output to your `stderr`.
+Both standard output and standard error output are forwarded to
+`git-send-pack` on the other end.