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 branch 144from getting rebased. 145 146 147post-checkout 148~~~~~~~~~~~~~ 149 150This hook is invoked when a 'git checkout' is run after having updated the 151worktree. The hook is given three parameters: the ref of the previous HEAD, 152the ref of the new HEAD (which may or may not have changed), and a flag 153indicating whether the checkout was a branch checkout (changing branches, 154flag=1) or a file checkout (retrieving a file from the index, flag=0). 155This hook cannot affect the outcome of 'git checkout'. 156 157It is also run after 'git clone', unless the --no-checkout (-n) option is 158used. The first parameter given to the hook is the null-ref, the second the 159ref of the new HEAD and the flag is always 1. 160 161This hook can be used to perform repository validity checks, auto-display 162differences from the previous HEAD if different, or set working dir metadata 163properties. 164 165post-merge 166~~~~~~~~~~ 167 168This hook is invoked by 'git merge', which happens when a 'git pull' 169is done on a local repository. The hook takes a single parameter, a status 170flag specifying whether or not the merge being done was a squash merge. 171This hook cannot affect the outcome of 'git merge' and is not executed, 172if the merge failed due to conflicts. 173 174This hook can be used in conjunction with a corresponding pre-commit hook to 175save and restore any form of metadata associated with the working tree 176(eg: permissions/ownership, ACLS, etc). See contrib/hooks/setgitperms.perl 177for an example of how to do this. 178 179pre-push 180~~~~~~~~ 181 182This hook is called by 'git push' and can be used to prevent a push from taking 183place. The hook is called with two parameters which provide the name and 184location of the destination remote, if a named remote is not being used both 185values will be the same. 186 187Information about what is to be pushed is provided on the hook's standard 188input with lines of the form: 189 190 <local ref> SP <local sha1> SP <remote ref> SP <remote sha1> LF 191 192For instance, if the command +git push origin master:foreign+ were run the 193hook would receive a line like the following: 194 195 refs/heads/master 67890 refs/heads/foreign 12345 196 197although the full, 40-character SHA1s would be supplied. If the foreign ref 198does not yet exist the `<remote SHA1>` will be 40 `0`. If a ref is to be 199deleted, the `<local ref>` will be supplied as `(delete)` and the `<local 200SHA1>` will be 40 `0`. If the local commit was specified by something other 201than a name which could be expanded (such as `HEAD~`, or a SHA1) it will be 202supplied as it was originally given. 203 204If this hook exits with a non-zero status, 'git push' will abort without 205pushing anything. Information about why the push is rejected may be sent 206to the user by writing to standard error. 207 208[[pre-receive]] 209pre-receive 210~~~~~~~~~~~ 211 212This hook is invoked by 'git-receive-pack' on the remote repository, 213which happens when a 'git push' is done on a local repository. 214Just before starting to update refs on the remote repository, the 215pre-receive hook is invoked. Its exit status determines the success 216or failure of the update. 217 218This hook executes once for the receive operation. It takes no 219arguments, but for each ref to be updated it receives on standard 220input a line of the format: 221 222 <old-value> SP <new-value> SP <ref-name> LF 223 224where `<old-value>` is the old object name stored in the ref, 225`<new-value>` is the new object name to be stored in the ref and 226`<ref-name>` is the full name of the ref. 227When creating a new ref, `<old-value>` is 40 `0`. 228 229If the hook exits with non-zero status, none of the refs will be 230updated. If the hook exits with zero, updating of individual refs can 231still be prevented by the <<update,'update'>> hook. 232 233Both standard output and standard error output are forwarded to 234'git send-pack' on the other end, so you can simply `echo` messages 235for the user. 236 237[[update]] 238update 239~~~~~~ 240 241This hook is invoked by 'git-receive-pack' on the remote repository, 242which happens when a 'git push' is done on a local repository. 243Just before updating the ref on the remote repository, the update hook 244is invoked. Its exit status determines the success or failure of 245the ref update. 246 247The hook executes once for each ref to be updated, and takes 248three parameters: 249 250 - the name of the ref being updated, 251 - the old object name stored in the ref, 252 - and the new objectname to be stored in the ref. 253 254A zero exit from the update hook allows the ref to be updated. 255Exiting with a non-zero status prevents 'git-receive-pack' 256from updating that ref. 257 258This hook can be used to prevent 'forced' update on certain refs by 259making sure that the object name is a commit object that is a 260descendant of the commit object named by the old object name. 261That is, to enforce a "fast-forward only" policy. 262 263It could also be used to log the old..new status. However, it 264does not know the entire set of branches, so it would end up 265firing one e-mail per ref when used naively, though. The 266<<post-receive,'post-receive'>> hook is more suited to that. 267 268Another use suggested on the mailing list is to use this hook to 269implement access control which is finer grained than the one 270based on filesystem group. 271 272Both standard output and standard error output are forwarded to 273'git send-pack' on the other end, so you can simply `echo` messages 274for the user. 275 276The default 'update' hook, when enabled--and with 277`hooks.allowunannotated` config option unset or set to false--prevents 278unannotated tags to be pushed. 279 280[[post-receive]] 281post-receive 282~~~~~~~~~~~~ 283 284This hook is invoked by 'git-receive-pack' on the remote repository, 285which happens when a 'git push' is done on a local repository. 286It executes on the remote repository once after all the refs have 287been updated. 288 289This hook executes once for the receive operation. It takes no 290arguments, but gets the same information as the 291<<pre-receive,'pre-receive'>> 292hook does on its standard input. 293 294This hook does not affect the outcome of 'git-receive-pack', as it 295is called after the real work is done. 296 297This supersedes the <<post-update,'post-update'>> hook in that it gets 298both old and new values of all the refs in addition to their 299names. 300 301Both standard output and standard error output are forwarded to 302'git send-pack' on the other end, so you can simply `echo` messages 303for the user. 304 305The default 'post-receive' hook is empty, but there is 306a sample script `post-receive-email` provided in the `contrib/hooks` 307directory in Git distribution, which implements sending commit 308emails. 309 310[[post-update]] 311post-update 312~~~~~~~~~~~ 313 314This hook is invoked by 'git-receive-pack' on the remote repository, 315which happens when a 'git push' is done on a local repository. 316It executes on the remote repository once after all the refs have 317been updated. 318 319It takes a variable number of parameters, each of which is the 320name of ref that was actually updated. 321 322This hook is meant primarily for notification, and cannot affect 323the outcome of 'git-receive-pack'. 324 325The 'post-update' hook can tell what are the heads that were pushed, 326but it does not know what their original and updated values are, 327so it is a poor place to do log old..new. The 328<<post-receive,'post-receive'>> hook does get both original and 329updated values of the refs. You might consider it instead if you need 330them. 331 332When enabled, the default 'post-update' hook runs 333'git update-server-info' to keep the information used by dumb 334transports (e.g., HTTP) up-to-date. If you are publishing 335a Git repository that is accessible via HTTP, you should 336probably enable this hook. 337 338Both standard output and standard error output are forwarded to 339'git send-pack' on the other end, so you can simply `echo` messages 340for the user. 341 342pre-auto-gc 343~~~~~~~~~~~ 344 345This hook is invoked by 'git gc --auto'. It takes no parameter, and 346exiting with non-zero status from this script causes the 'git gc --auto' 347to abort. 348 349post-rewrite 350~~~~~~~~~~~~ 351 352This hook is invoked by commands that rewrite commits (`git commit 353--amend`, 'git-rebase'; currently 'git-filter-branch' does 'not' call 354it!). Its first argument denotes the command it was invoked by: 355currently one of `amend` or `rebase`. Further command-dependent 356arguments may be passed in the future. 357 358The hook receives a list of the rewritten commits on stdin, in the 359format 360 361 <old-sha1> SP <new-sha1> [ SP <extra-info> ] LF 362 363The 'extra-info' is again command-dependent. If it is empty, the 364preceding SP is also omitted. Currently, no commands pass any 365'extra-info'. 366 367The hook always runs after the automatic note copying (see 368"notes.rewrite.<command>" in linkgit:git-config.txt[1]) has happened, and 369thus has access to these notes. 370 371The following command-specific comments apply: 372 373rebase:: 374 For the 'squash' and 'fixup' operation, all commits that were 375 squashed are listed as being rewritten to the squashed commit. 376 This means that there will be several lines sharing the same 377 'new-sha1'. 378+ 379The commits are guaranteed to be listed in the order that they were 380processed by rebase. 381 382 383GIT 384--- 385Part of the linkgit:git[1] suite