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.