1githooks(5) 2=========== 3 4NAME 5---- 6githooks - Hooks used by git 7 8SYNOPSIS 9-------- 10$GIT_DIR/hooks/* 11 12 13DESCRIPTION 14----------- 15 16Hooks are little scripts you can place in `$GIT_DIR/hooks` 17directory to trigger action at certain points. When 18'git-init' is run, a handful example hooks are copied in the 19`hooks` directory of the new repository, but by default they are 20all disabled. To enable a hook, rename it by removing its `.sample` 21suffix. 22 23This document describes the currently defined hooks. 24 25applypatch-msg 26-------------- 27 28This hook is invoked by 'git-am' script. It takes a single 29parameter, the name of the file that holds the proposed commit 30log message. Exiting with non-zero status causes 31'git-am' to abort before applying the patch. 32 33The hook is allowed to edit the message file in place, and can 34be used to normalize the message into some project standard 35format (if the project has one). It can also be used to refuse 36the commit after inspecting the message file. 37 38The default 'applypatch-msg' hook, when enabled, runs the 39'commit-msg' hook, if the latter is enabled. 40 41pre-applypatch 42-------------- 43 44This hook is invoked by 'git-am'. It takes no parameter, and is 45invoked after the patch is applied, but before a commit is made. 46 47If it exits with non-zero status, then the working tree will not be 48committed after applying the patch. 49 50It can be used to inspect the current working tree and refuse to 51make a commit if it does not pass certain test. 52 53The default 'pre-applypatch' hook, when enabled, runs the 54'pre-commit' hook, if the latter is enabled. 55 56post-applypatch 57--------------- 58 59This hook is invoked by 'git-am'. It takes no parameter, 60and is invoked after the patch is applied and a commit is made. 61 62This hook is meant primarily for notification, and cannot affect 63the outcome of 'git-am'. 64 65pre-commit 66---------- 67 68This hook is invoked by 'git-commit', and can be bypassed 69with `\--no-verify` option. It takes no parameter, and is 70invoked before obtaining the proposed commit log message and 71making a commit. Exiting with non-zero status from this script 72causes the 'git-commit' to abort. 73 74The default 'pre-commit' hook, when enabled, catches introduction 75of lines with trailing whitespaces and aborts the commit when 76such a line is found. 77 78All the 'git-commit' hooks are invoked with the environment 79variable `GIT_EDITOR=:` if the command will not bring up an editor 80to modify the commit message. 81 82prepare-commit-msg 83------------------ 84 85This hook is invoked by 'git-commit' right after preparing the 86default log message, and before the editor is started. 87 88It takes one to three parameters. The first is the name of the file 89that the commit log message. The second is the source of the commit 90message, and can be: `message` (if a `-m` or `-F` option was 91given); `template` (if a `-t` option was given or the 92configuration option `commit.template` is set); `merge` (if the 93commit is a merge or a `.git/MERGE_MSG` file exists); `squash` 94(if a `.git/SQUASH_MSG` file exists); or `commit`, followed by 95a commit SHA1 (if a `-c`, `-C` or `\--amend` option was given). 96 97If the exit status is non-zero, 'git-commit' will abort. 98 99The purpose of the hook is to edit the message file in place, and 100it is not suppressed by the `\--no-verify` option. A non-zero exit 101means a failure of the hook and aborts the commit. It should not 102be used as replacement for pre-commit hook. 103 104The sample `prepare-commit-msg` hook that comes with git comments 105out the `Conflicts:` part of a merge's commit message. 106 107commit-msg 108---------- 109 110This hook is invoked by 'git-commit', and can be bypassed 111with `\--no-verify` option. It takes a single parameter, the 112name of the file that holds the proposed commit log message. 113Exiting with non-zero status causes the 'git-commit' to 114abort. 115 116The hook is allowed to edit the message file in place, and can 117be used to normalize the message into some project standard 118format (if the project has one). It can also be used to refuse 119the commit after inspecting the message file. 120 121The default 'commit-msg' hook, when enabled, detects duplicate 122"Signed-off-by" lines, and aborts the commit if one is found. 123 124post-commit 125----------- 126 127This hook is invoked by 'git-commit'. It takes no 128parameter, and is invoked after a commit is made. 129 130This hook is meant primarily for notification, and cannot affect 131the outcome of 'git-commit'. 132 133post-checkout 134----------- 135 136This hook is invoked when a 'git-checkout' is run after having updated the 137worktree. The hook is given three parameters: the ref of the previous HEAD, 138the ref of the new HEAD (which may or may not have changed), and a flag 139indicating whether the checkout was a branch checkout (changing branches, 140flag=1) or a file checkout (retrieving a file from the index, flag=0). 141This hook cannot affect the outcome of 'git-checkout'. 142 143This hook can be used to perform repository validity checks, auto-display 144differences from the previous HEAD if different, or set working dir metadata 145properties. 146 147post-merge 148----------- 149 150This hook is invoked by 'git-merge', which happens when a 'git-pull' 151is done on a local repository. The hook takes a single parameter, a status 152flag specifying whether or not the merge being done was a squash merge. 153This hook cannot affect the outcome of 'git-merge' and is not executed, 154if the merge failed due to conflicts. 155 156This hook can be used in conjunction with a corresponding pre-commit hook to 157save and restore any form of metadata associated with the working tree 158(eg: permissions/ownership, ACLS, etc). See contrib/hooks/setgitperms.perl 159for an example of how to do this. 160 161[[pre-receive]] 162pre-receive 163----------- 164 165This hook is invoked by 'git-receive-pack' on the remote repository, 166which happens when a 'git-push' is done on a local repository. 167Just before starting to update refs on the remote repository, the 168pre-receive hook is invoked. Its exit status determines the success 169or failure of the update. 170 171This hook executes once for the receive operation. It takes no 172arguments, but for each ref to be updated it receives on standard 173input a line of the format: 174 175 <old-value> SP <new-value> SP <ref-name> LF 176 177where `<old-value>` is the old object name stored in the ref, 178`<new-value>` is the new object name to be stored in the ref and 179`<ref-name>` is the full name of the ref. 180When creating a new ref, `<old-value>` is 40 `0`. 181 182If the hook exits with non-zero status, none of the refs will be 183updated. If the hook exits with zero, updating of individual refs can 184still be prevented by the <<update,'update'>> hook. 185 186Both standard output and standard error output are forwarded to 187'git-send-pack' on the other end, so you can simply `echo` messages 188for the user. 189 190[[update]] 191update 192------ 193 194This hook is invoked by 'git-receive-pack' on the remote repository, 195which happens when a 'git-push' is done on a local repository. 196Just before updating the ref on the remote repository, the update hook 197is invoked. Its exit status determines the success or failure of 198the ref update. 199 200The hook executes once for each ref to be updated, and takes 201three parameters: 202 203 - the name of the ref being updated, 204 - the old object name stored in the ref, 205 - and the new objectname to be stored in the ref. 206 207A zero exit from the update hook allows the ref to be updated. 208Exiting with a non-zero status prevents 'git-receive-pack' 209from updating that ref. 210 211This hook can be used to prevent 'forced' update on certain refs by 212making sure that the object name is a commit object that is a 213descendant of the commit object named by the old object name. 214That is, to enforce a "fast forward only" policy. 215 216It could also be used to log the old..new status. However, it 217does not know the entire set of branches, so it would end up 218firing one e-mail per ref when used naively, though. The 219<<post-receive,'post-receive'>> hook is more suited to that. 220 221Another use suggested on the mailing list is to use this hook to 222implement access control which is finer grained than the one 223based on filesystem group. 224 225Both standard output and standard error output are forwarded to 226'git-send-pack' on the other end, so you can simply `echo` messages 227for the user. 228 229The default 'update' hook, when enabled--and with 230`hooks.allowunannotated` config option turned on--prevents 231unannotated tags to be pushed. 232 233[[post-receive]] 234post-receive 235------------ 236 237This hook is invoked by 'git-receive-pack' on the remote repository, 238which happens when a 'git-push' is done on a local repository. 239It executes on the remote repository once after all the refs have 240been updated. 241 242This hook executes once for the receive operation. It takes no 243arguments, but gets the same information as the 244<<pre-receive,'pre-receive'>> 245hook does on its standard input. 246 247This hook does not affect the outcome of 'git-receive-pack', as it 248is called after the real work is done. 249 250This supersedes the <<post-update,'post-update'>> hook in that it gets 251both old and new values of all the refs in addition to their 252names. 253 254Both standard output and standard error output are forwarded to 255'git-send-pack' on the other end, so you can simply `echo` messages 256for the user. 257 258The default 'post-receive' hook is empty, but there is 259a sample script `post-receive-email` provided in the `contrib/hooks` 260directory in git distribution, which implements sending commit 261emails. 262 263[[post-update]] 264post-update 265----------- 266 267This hook is invoked by 'git-receive-pack' on the remote repository, 268which happens when a 'git-push' is done on a local repository. 269It executes on the remote repository once after all the refs have 270been updated. 271 272It takes a variable number of parameters, each of which is the 273name of ref that was actually updated. 274 275This hook is meant primarily for notification, and cannot affect 276the outcome of 'git-receive-pack'. 277 278The 'post-update' hook can tell what are the heads that were pushed, 279but it does not know what their original and updated values are, 280so it is a poor place to do log old..new. The 281<<post-receive,'post-receive'>> hook does get both original and 282updated values of the refs. You might consider it instead if you need 283them. 284 285When enabled, the default 'post-update' hook runs 286'git-update-server-info' to keep the information used by dumb 287transports (e.g., HTTP) up-to-date. If you are publishing 288a git repository that is accessible via HTTP, you should 289probably enable this hook. 290 291Both standard output and standard error output are forwarded to 292'git-send-pack' on the other end, so you can simply `echo` messages 293for the user. 294 295pre-auto-gc 296----------- 297 298This hook is invoked by 'git-gc --auto'. It takes no parameter, and 299exiting with non-zero status from this script causes the 'git-gc --auto' 300to abort. 301 302GIT 303--- 304Part of the linkgit:git[1] suite