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 133pre-rebase 134---------- 135 136This hook is called by 'git-rebase' and can be used to prevent a branch 137from getting rebased. 138 139 140post-checkout 141----------- 142 143This hook is invoked when a 'git-checkout' is run after having updated the 144worktree. The hook is given three parameters: the ref of the previous HEAD, 145the ref of the new HEAD (which may or may not have changed), and a flag 146indicating whether the checkout was a branch checkout (changing branches, 147flag=1) or a file checkout (retrieving a file from the index, flag=0). 148This hook cannot affect the outcome of 'git-checkout'. 149 150This hook can be used to perform repository validity checks, auto-display 151differences from the previous HEAD if different, or set working dir metadata 152properties. 153 154post-merge 155----------- 156 157This hook is invoked by 'git-merge', which happens when a 'git-pull' 158is done on a local repository. The hook takes a single parameter, a status 159flag specifying whether or not the merge being done was a squash merge. 160This hook cannot affect the outcome of 'git-merge' and is not executed, 161if the merge failed due to conflicts. 162 163This hook can be used in conjunction with a corresponding pre-commit hook to 164save and restore any form of metadata associated with the working tree 165(eg: permissions/ownership, ACLS, etc). See contrib/hooks/setgitperms.perl 166for an example of how to do this. 167 168[[pre-receive]] 169pre-receive 170----------- 171 172This hook is invoked by 'git-receive-pack' on the remote repository, 173which happens when a 'git-push' is done on a local repository. 174Just before starting to update refs on the remote repository, the 175pre-receive hook is invoked. Its exit status determines the success 176or failure of the update. 177 178This hook executes once for the receive operation. It takes no 179arguments, but for each ref to be updated it receives on standard 180input a line of the format: 181 182 <old-value> SP <new-value> SP <ref-name> LF 183 184where `<old-value>` is the old object name stored in the ref, 185`<new-value>` is the new object name to be stored in the ref and 186`<ref-name>` is the full name of the ref. 187When creating a new ref, `<old-value>` is 40 `0`. 188 189If the hook exits with non-zero status, none of the refs will be 190updated. If the hook exits with zero, updating of individual refs can 191still be prevented by the <<update,'update'>> hook. 192 193Both standard output and standard error output are forwarded to 194'git-send-pack' on the other end, so you can simply `echo` messages 195for the user. 196 197[[update]] 198update 199------ 200 201This hook is invoked by 'git-receive-pack' on the remote repository, 202which happens when a 'git-push' is done on a local repository. 203Just before updating the ref on the remote repository, the update hook 204is invoked. Its exit status determines the success or failure of 205the ref update. 206 207The hook executes once for each ref to be updated, and takes 208three parameters: 209 210 - the name of the ref being updated, 211 - the old object name stored in the ref, 212 - and the new objectname to be stored in the ref. 213 214A zero exit from the update hook allows the ref to be updated. 215Exiting with a non-zero status prevents 'git-receive-pack' 216from updating that ref. 217 218This hook can be used to prevent 'forced' update on certain refs by 219making sure that the object name is a commit object that is a 220descendant of the commit object named by the old object name. 221That is, to enforce a "fast forward only" policy. 222 223It could also be used to log the old..new status. However, it 224does not know the entire set of branches, so it would end up 225firing one e-mail per ref when used naively, though. The 226<<post-receive,'post-receive'>> hook is more suited to that. 227 228Another use suggested on the mailing list is to use this hook to 229implement access control which is finer grained than the one 230based on filesystem group. 231 232Both standard output and standard error output are forwarded to 233'git-send-pack' on the other end, so you can simply `echo` messages 234for the user. 235 236The default 'update' hook, when enabled--and with 237`hooks.allowunannotated` config option turned on--prevents 238unannotated tags to be pushed. 239 240[[post-receive]] 241post-receive 242------------ 243 244This hook is invoked by 'git-receive-pack' on the remote repository, 245which happens when a 'git-push' is done on a local repository. 246It executes on the remote repository once after all the refs have 247been updated. 248 249This hook executes once for the receive operation. It takes no 250arguments, but gets the same information as the 251<<pre-receive,'pre-receive'>> 252hook does on its standard input. 253 254This hook does not affect the outcome of 'git-receive-pack', as it 255is called after the real work is done. 256 257This supersedes the <<post-update,'post-update'>> hook in that it gets 258both old and new values of all the refs in addition to their 259names. 260 261Both standard output and standard error output are forwarded to 262'git-send-pack' on the other end, so you can simply `echo` messages 263for the user. 264 265The default 'post-receive' hook is empty, but there is 266a sample script `post-receive-email` provided in the `contrib/hooks` 267directory in git distribution, which implements sending commit 268emails. 269 270[[post-update]] 271post-update 272----------- 273 274This hook is invoked by 'git-receive-pack' on the remote repository, 275which happens when a 'git-push' is done on a local repository. 276It executes on the remote repository once after all the refs have 277been updated. 278 279It takes a variable number of parameters, each of which is the 280name of ref that was actually updated. 281 282This hook is meant primarily for notification, and cannot affect 283the outcome of 'git-receive-pack'. 284 285The 'post-update' hook can tell what are the heads that were pushed, 286but it does not know what their original and updated values are, 287so it is a poor place to do log old..new. The 288<<post-receive,'post-receive'>> hook does get both original and 289updated values of the refs. You might consider it instead if you need 290them. 291 292When enabled, the default 'post-update' hook runs 293'git-update-server-info' to keep the information used by dumb 294transports (e.g., HTTP) up-to-date. If you are publishing 295a git repository that is accessible via HTTP, you should 296probably enable this hook. 297 298Both standard output and standard error output are forwarded to 299'git-send-pack' on the other end, so you can simply `echo` messages 300for the user. 301 302pre-auto-gc 303----------- 304 305This hook is invoked by 'git-gc --auto'. It takes no parameter, and 306exiting with non-zero status from this script causes the 'git-gc --auto' 307to abort. 308 309GIT 310--- 311Part of the linkgit:git[1] suite