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 of example hooks are copied into 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 23NOTE: It is also a requirement for a given hook to be executable. 24However - in a freshly initialized repository - the `.sample` files are 25executable by default. 26 27This document describes the currently defined hooks. 28 29HOOKS 30----- 31 32applypatch-msg 33~~~~~~~~~~~~~~ 34 35This hook is invoked by 'git am' script. It takes a single 36parameter, the name of the file that holds the proposed commit 37log message. Exiting with non-zero status causes 38'git am' to abort before applying the patch. 39 40The hook is allowed to edit the message file in place, and can 41be used to normalize the message into some project standard 42format (if the project has one). It can also be used to refuse 43the commit after inspecting the message file. 44 45The default 'applypatch-msg' hook, when enabled, runs the 46'commit-msg' hook, if the latter is enabled. 47 48pre-applypatch 49~~~~~~~~~~~~~~ 50 51This hook is invoked by 'git am'. It takes no parameter, and is 52invoked after the patch is applied, but before a commit is made. 53 54If it exits with non-zero status, then the working tree will not be 55committed after applying the patch. 56 57It can be used to inspect the current working tree and refuse to 58make a commit if it does not pass certain test. 59 60The default 'pre-applypatch' hook, when enabled, runs the 61'pre-commit' hook, if the latter is enabled. 62 63post-applypatch 64~~~~~~~~~~~~~~~ 65 66This hook is invoked by 'git am'. It takes no parameter, 67and is invoked after the patch is applied and a commit is made. 68 69This hook is meant primarily for notification, and cannot affect 70the outcome of 'git am'. 71 72pre-commit 73~~~~~~~~~~ 74 75This hook is invoked by 'git commit', and can be bypassed 76with `--no-verify` option. It takes no parameter, and is 77invoked before obtaining the proposed commit log message and 78making a commit. Exiting with non-zero status from this script 79causes the 'git commit' to abort. 80 81The default 'pre-commit' hook, when enabled, catches introduction 82of lines with trailing whitespaces and aborts the commit when 83such a line is found. 84 85All the 'git commit' hooks are invoked with the environment 86variable `GIT_EDITOR=:` if the command will not bring up an editor 87to modify the commit message. 88 89prepare-commit-msg 90~~~~~~~~~~~~~~~~~~ 91 92This hook is invoked by 'git commit' right after preparing the 93default log message, and before the editor is started. 94 95It takes one to three parameters. The first is the name of the file 96that contains the commit log message. The second is the source of the commit 97message, and can be: `message` (if a `-m` or `-F` option was 98given); `template` (if a `-t` option was given or the 99configuration option `commit.template` is set); `merge` (if the 100commit is a merge or a `.git/MERGE_MSG` file exists); `squash` 101(if a `.git/SQUASH_MSG` file exists); or `commit`, followed by 102a commit SHA1 (if a `-c`, `-C` or `--amend` option was given). 103 104If the exit status is non-zero, 'git commit' will abort. 105 106The purpose of the hook is to edit the message file in place, and 107it is not suppressed by the `--no-verify` option. A non-zero exit 108means a failure of the hook and aborts the commit. It should not 109be used as replacement for pre-commit hook. 110 111The sample `prepare-commit-msg` hook that comes with git comments 112out the `Conflicts:` part of a merge's commit message. 113 114commit-msg 115~~~~~~~~~~ 116 117This hook is invoked by 'git commit', and can be bypassed 118with `--no-verify` option. It takes a single parameter, the 119name of the file that holds the proposed commit log message. 120Exiting with non-zero status causes the 'git commit' to 121abort. 122 123The hook is allowed to edit the message file in place, and can 124be used to normalize the message into some project standard 125format (if the project has one). It can also be used to refuse 126the commit after inspecting the message file. 127 128The default 'commit-msg' hook, when enabled, detects duplicate 129"Signed-off-by" lines, and aborts the commit if one is found. 130 131post-commit 132~~~~~~~~~~~ 133 134This hook is invoked by 'git commit'. It takes no 135parameter, and is invoked after a commit is made. 136 137This hook is meant primarily for notification, and cannot affect 138the outcome of 'git commit'. 139 140pre-rebase 141~~~~~~~~~~ 142 143This hook is called by 'git rebase' and can be used to prevent a 144branch from getting rebased. The hook may be called with one or 145two parameters. The first parameter is the upstream from which 146the series was forked. The second parameter is the branch being 147rebased, and is not set when rebasing the current branch. 148 149post-checkout 150~~~~~~~~~~~~~ 151 152This hook is invoked when a 'git checkout' is run after having updated the 153worktree. The hook is given three parameters: the ref of the previous HEAD, 154the ref of the new HEAD (which may or may not have changed), and a flag 155indicating whether the checkout was a branch checkout (changing branches, 156flag=1) or a file checkout (retrieving a file from the index, flag=0). 157This hook cannot affect the outcome of 'git checkout'. 158 159It is also run after 'git clone', unless the --no-checkout (-n) option is 160used. The first parameter given to the hook is the null-ref, the second the 161ref of the new HEAD and the flag is always 1. 162 163This hook can be used to perform repository validity checks, auto-display 164differences from the previous HEAD if different, or set working dir metadata 165properties. 166 167post-merge 168~~~~~~~~~~ 169 170This hook is invoked by 'git merge', which happens when a 'git pull' 171is done on a local repository. The hook takes a single parameter, a status 172flag specifying whether or not the merge being done was a squash merge. 173This hook cannot affect the outcome of 'git merge' and is not executed, 174if the merge failed due to conflicts. 175 176This hook can be used in conjunction with a corresponding pre-commit hook to 177save and restore any form of metadata associated with the working tree 178(eg: permissions/ownership, ACLS, etc). See contrib/hooks/setgitperms.perl 179for an example of how to do this. 180 181[[pre-receive]] 182pre-receive 183~~~~~~~~~~~ 184 185This hook is invoked by 'git-receive-pack' on the remote repository, 186which happens when a 'git push' is done on a local repository. 187Just before starting to update refs on the remote repository, the 188pre-receive hook is invoked. Its exit status determines the success 189or failure of the update. 190 191This hook executes once for the receive operation. It takes no 192arguments, but for each ref to be updated it receives on standard 193input a line of the format: 194 195 <old-value> SP <new-value> SP <ref-name> LF 196 197where `<old-value>` is the old object name stored in the ref, 198`<new-value>` is the new object name to be stored in the ref and 199`<ref-name>` is the full name of the ref. 200When creating a new ref, `<old-value>` is 40 `0`. 201 202If the hook exits with non-zero status, none of the refs will be 203updated. If the hook exits with zero, updating of individual refs can 204still be prevented by the <<update,'update'>> hook. 205 206Both standard output and standard error output are forwarded to 207'git send-pack' on the other end, so you can simply `echo` messages 208for the user. 209 210[[update]] 211update 212~~~~~~ 213 214This hook is invoked by 'git-receive-pack' on the remote repository, 215which happens when a 'git push' is done on a local repository. 216Just before updating the ref on the remote repository, the update hook 217is invoked. Its exit status determines the success or failure of 218the ref update. 219 220The hook executes once for each ref to be updated, and takes 221three parameters: 222 223 - the name of the ref being updated, 224 - the old object name stored in the ref, 225 - and the new objectname to be stored in the ref. 226 227A zero exit from the update hook allows the ref to be updated. 228Exiting with a non-zero status prevents 'git-receive-pack' 229from updating that ref. 230 231This hook can be used to prevent 'forced' update on certain refs by 232making sure that the object name is a commit object that is a 233descendant of the commit object named by the old object name. 234That is, to enforce a "fast-forward only" policy. 235 236It could also be used to log the old..new status. However, it 237does not know the entire set of branches, so it would end up 238firing one e-mail per ref when used naively, though. The 239<<post-receive,'post-receive'>> hook is more suited to that. 240 241Another use suggested on the mailing list is to use this hook to 242implement access control which is finer grained than the one 243based on filesystem group. 244 245Both standard output and standard error output are forwarded to 246'git send-pack' on the other end, so you can simply `echo` messages 247for the user. 248 249The default 'update' hook, when enabled--and with 250`hooks.allowunannotated` config option unset or set to false--prevents 251unannotated tags to be pushed. 252 253[[post-receive]] 254post-receive 255~~~~~~~~~~~~ 256 257This hook is invoked by 'git-receive-pack' on the remote repository, 258which happens when a 'git push' is done on a local repository. 259It executes on the remote repository once after all the refs have 260been updated. 261 262This hook executes once for the receive operation. It takes no 263arguments, but gets the same information as the 264<<pre-receive,'pre-receive'>> 265hook does on its standard input. 266 267This hook does not affect the outcome of 'git-receive-pack', as it 268is called after the real work is done. 269 270This supersedes the <<post-update,'post-update'>> hook in that it gets 271both old and new values of all the refs in addition to their 272names. 273 274Both standard output and standard error output are forwarded to 275'git send-pack' on the other end, so you can simply `echo` messages 276for the user. 277 278The default 'post-receive' hook is empty, but there is 279a sample script `post-receive-email` provided in the `contrib/hooks` 280directory in git distribution, which implements sending commit 281emails. 282 283[[post-update]] 284post-update 285~~~~~~~~~~~ 286 287This hook is invoked by 'git-receive-pack' on the remote repository, 288which happens when a 'git push' is done on a local repository. 289It executes on the remote repository once after all the refs have 290been updated. 291 292It takes a variable number of parameters, each of which is the 293name of ref that was actually updated. 294 295This hook is meant primarily for notification, and cannot affect 296the outcome of 'git-receive-pack'. 297 298The 'post-update' hook can tell what are the heads that were pushed, 299but it does not know what their original and updated values are, 300so it is a poor place to do log old..new. The 301<<post-receive,'post-receive'>> hook does get both original and 302updated values of the refs. You might consider it instead if you need 303them. 304 305When enabled, the default 'post-update' hook runs 306'git update-server-info' to keep the information used by dumb 307transports (e.g., HTTP) up-to-date. If you are publishing 308a git repository that is accessible via HTTP, you should 309probably enable this hook. 310 311Both standard output and standard error output are forwarded to 312'git send-pack' on the other end, so you can simply `echo` messages 313for the user. 314 315pre-auto-gc 316~~~~~~~~~~~ 317 318This hook is invoked by 'git gc --auto'. It takes no parameter, and 319exiting with non-zero status from this script causes the 'git gc --auto' 320to abort. 321 322post-rewrite 323~~~~~~~~~~~~ 324 325This hook is invoked by commands that rewrite commits (`git commit 326--amend`, 'git-rebase'; currently 'git-filter-branch' does 'not' call 327it!). Its first argument denotes the command it was invoked by: 328currently one of `amend` or `rebase`. Further command-dependent 329arguments may be passed in the future. 330 331The hook receives a list of the rewritten commits on stdin, in the 332format 333 334 <old-sha1> SP <new-sha1> [ SP <extra-info> ] LF 335 336The 'extra-info' is again command-dependent. If it is empty, the 337preceding SP is also omitted. Currently, no commands pass any 338'extra-info'. 339 340The hook always runs after the automatic note copying (see 341"notes.rewrite.<command>" in linkgit:git-config.txt[1]) has happened, and 342thus has access to these notes. 343 344The following command-specific comments apply: 345 346rebase:: 347 For the 'squash' and 'fixup' operation, all commits that were 348 squashed are listed as being rewritten to the squashed commit. 349 This means that there will be several lines sharing the same 350 'new-sha1'. 351+ 352The commits are guaranteed to be listed in the order that they were 353processed by rebase. 354 355 356GIT 357--- 358Part of the linkgit:git[1] suite