Documentation / hooks.txton commit Alphabetize the glossary. (aa9b157)
   1Hooks used by git
   2=================
   3
   4Hooks are little scripts you can place in `$GIT_DIR/hooks`
   5directory to trigger action at certain points.  When
   6`git-init-db` is run, a handful example hooks are copied in the
   7`hooks` directory of the new repository, but by default they are
   8all disabled.  To enable a hook, make it executable with `chmod
   9+x`.
  10
  11This document describes the currently defined hooks.
  12
  13applypatch-msg
  14--------------
  15
  16This hook is invoked by `git-applypatch` script, which is
  17typically invoked by `git-applymbox`.  It takes a single
  18parameter, the name of the file that holds the proposed commit
  19log message.  Exiting with non-zero status causes the
  20'git-applypatch' to abort before applying the patch.
  21
  22The hook is allowed to edit the message file in place, and can
  23be used to normalize the message into some project standard
  24format (if the project has one). It can also be used to refuse
  25the commit after inspecting the message file.
  26
  27The default applypatch-msg hook, when enabled, runs the
  28commit-msg hook, if the latter is enabled.
  29
  30pre-applypatch
  31--------------
  32
  33This hook is invoked by `git-applypatch` script, which is
  34typically invoked by `git-applymbox`.  It takes no parameter,
  35and is invoked after the patch is applied, but before a commit
  36is made.  Exiting with non-zero status causes the working tree
  37after application of the patch not committed.
  38
  39It can be used to inspect the current working tree and refuse to
  40make a commit if it does not pass certain test.
  41
  42The default pre-applypatch hook, when enabled, runs the
  43pre-commit hook, if the latter is enabled.
  44
  45post-applypatch
  46---------------
  47
  48This hook is invoked by `git-applypatch` script, which is
  49typically invoked by `git-applymbox`.  It takes no parameter,
  50and is invoked after the patch is applied and a commit is made.
  51
  52This hook is meant primarily for notification, and cannot affect
  53the outcome of `git-applypatch`.
  54
  55pre-commit
  56----------
  57
  58This hook is invoked by `git-commit`, and can be bypassed
  59with `\--no-verify` option.  It takes no parameter, and is
  60invoked before obtaining the proposed commit log message and
  61making a commit.  Exiting with non-zero status from this script
  62causes the `git-commit` to abort.
  63
  64The default pre-commit hook, when enabled, catches introduction
  65of lines with trailing whitespaces and aborts the commit when
  66a such line is found.
  67
  68commit-msg
  69----------
  70
  71This hook is invoked by `git-commit`, and can be bypassed
  72with `\--no-verify` option.  It takes a single parameter, the
  73name of the file that holds the proposed commit log message.
  74Exiting with non-zero status causes the `git-commit` to
  75abort.
  76
  77The hook is allowed to edit the message file in place, and can
  78be used to normalize the message into some project standard
  79format (if the project has one). It can also be used to refuse
  80the commit after inspecting the message file.
  81
  82The default commit-msg hook, when enabled, detects duplicate
  83Signed-off-by: lines, and aborts the commit when one is found.
  84
  85post-commit
  86-----------
  87
  88This hook is invoked by `git-commit`.  It takes no
  89parameter, and is invoked after a commit is made.
  90
  91This hook is meant primarily for notification, and cannot affect
  92the outcome of `git-commit`.
  93
  94The default post-commit hook, when enabled, demonstrates how to
  95send out a commit notification e-mail.
  96
  97update
  98------
  99
 100This hook is invoked by `git-receive-pack` on the remote repository,
 101which is happens when a `git push` is done on a local repository.
 102Just before updating the ref on the remote repository, the update hook
 103is invoked.  It's exit status determins the success or failure of
 104the ref update.
 105
 106The hook executes once for each ref to be updated, and takes
 107three parameters:
 108    - the name of the ref being updated,
 109    - the old object name stored in the ref,
 110    - and the new objectname to be stored in the ref.
 111
 112A zero exit from the update hook allows the ref to be updated.
 113Exiting with a non-zero status prevents `git-receive-pack`
 114from updating the ref.
 115
 116This hook can be used to prevent 'forced' update on certain refs by
 117making sure that the object name is a commit object that is a
 118descendant of the commit object named by the old object name.
 119That is, to enforce a "fast forward only" policy.
 120
 121It could also be used to log the old..new status.  However, it
 122does not know the entire set of branches, so it would end up
 123firing one e-mail per ref when used naively, though.
 124
 125Another use suggested on the mailing list is to use this hook to
 126implement access control which is finer grained than the one
 127based on filesystem group.
 128
 129The standard output of this hook is sent to /dev/null; if you
 130want to report something to the git-send-pack on the other end,
 131you can redirect your output to your stderr.
 132
 133
 134post-update
 135-----------
 136
 137This hook is invoked by `git-receive-pack` on the remote repository,
 138which is happens when a `git push` is done on a local repository.
 139It executes on the remote repository once after all the refs have
 140been updated.
 141
 142It takes a variable number of parameters, each of which is the
 143name of ref that was actually updated.
 144
 145This hook is meant primarily for notification, and cannot affect
 146the outcome of `git-receive-pack`.
 147
 148The post-update hook can tell what are the heads that were pushed,
 149but it does not know what their original and updated values are,
 150so it is a poor place to do log old..new.
 151
 152The default post-update hook, when enabled, runs
 153`git-update-server-info` to keep the information used by dumb
 154transports (eg, http) up-to-date.  If you are publishing
 155a git repository that is accessible via http, you should
 156probably enable this hook.
 157
 158The standard output of this hook is sent to /dev/null; if you
 159want to report something to the git-send-pack on the other end,
 160you can redirect your output to your stderr.