1githooks(5) 2=========== 3 4NAME 5---- 6githooks - Hooks used by Git 7 8SYNOPSIS 9-------- 10$GIT_DIR/hooks/* 11 12 13DESCRIPTION 14----------- 15 16Hooks are programs you can place in the `$GIT_DIR/hooks` directory to 17trigger actions at certain points in git's execution. Hooks that don't 18have the executable bit set are ignored. 19 20Before Git invokes a hook, it changes its working directory to either 21the root of the working tree in a non-bare repository, or to the 22$GIT_DIR in a bare repository. 23 24Hooks can get their arguments via the environment, command-line 25arguments, and stdin. See the documentation for each hook below for 26details. 27 28'git init' may copy hooks to the new repository, depending on its 29configuration. See the "TEMPLATE DIRECTORY" section in 30linkgit:git-init[1] for details. When the rest of this document refers 31to "default hooks" it's talking about the default template shipped 32with Git. 33 34The currently supported hooks are described below. 35 36HOOKS 37----- 38 39applypatch-msg 40~~~~~~~~~~~~~~ 41 42This hook is invoked by 'git am'. It takes a single 43parameter, the name of the file that holds the proposed commit 44log message. Exiting with a non-zero status causes 'git am' to abort 45before applying the patch. 46 47The hook is allowed to edit the message file in place, and can 48be used to normalize the message into some project standard 49format. It can also be used to refuse the commit after inspecting 50the message file. 51 52The default 'applypatch-msg' hook, when enabled, runs the 53'commit-msg' hook, if the latter is enabled. 54 55pre-applypatch 56~~~~~~~~~~~~~~ 57 58This hook is invoked by 'git am'. It takes no parameter, and is 59invoked after the patch is applied, but before a commit is made. 60 61If it exits with non-zero status, then the working tree will not be 62committed after applying the patch. 63 64It can be used to inspect the current working tree and refuse to 65make a commit if it does not pass certain test. 66 67The default 'pre-applypatch' hook, when enabled, runs the 68'pre-commit' hook, if the latter is enabled. 69 70post-applypatch 71~~~~~~~~~~~~~~~ 72 73This hook is invoked by 'git am'. It takes no parameter, 74and is invoked after the patch is applied and a commit is made. 75 76This hook is meant primarily for notification, and cannot affect 77the outcome of 'git am'. 78 79pre-commit 80~~~~~~~~~~ 81 82This hook is invoked by 'git commit', and can be bypassed 83with the `--no-verify` option. It takes no parameters, and is 84invoked before obtaining the proposed commit log message and 85making a commit. Exiting with a non-zero status from this script 86causes the 'git commit' command to abort before creating a commit. 87 88The default 'pre-commit' hook, when enabled, catches introduction 89of lines with trailing whitespaces and aborts the commit when 90such a line is found. 91 92All the 'git commit' hooks are invoked with the environment 93variable `GIT_EDITOR=:` if the command will not bring up an editor 94to modify the commit message. 95 96prepare-commit-msg 97~~~~~~~~~~~~~~~~~~ 98 99This hook is invoked by 'git commit' right after preparing the 100default log message, and before the editor is started. 101 102It takes one to three parameters. The first is the name of the file 103that contains the commit log message. The second is the source of the commit 104message, and can be: `message` (if a `-m` or `-F` option was 105given); `template` (if a `-t` option was given or the 106configuration option `commit.template` is set); `merge` (if the 107commit is a merge or a `.git/MERGE_MSG` file exists); `squash` 108(if a `.git/SQUASH_MSG` file exists); or `commit`, followed by 109a commit SHA-1 (if a `-c`, `-C` or `--amend` option was given). 110 111If the exit status is non-zero, 'git commit' will abort. 112 113The purpose of the hook is to edit the message file in place, and 114it is not suppressed by the `--no-verify` option. A non-zero exit 115means a failure of the hook and aborts the commit. It should not 116be used as replacement for pre-commit hook. 117 118The sample `prepare-commit-msg` hook that comes with Git comments 119out the `Conflicts:` part of a merge's commit message. 120 121commit-msg 122~~~~~~~~~~ 123 124This hook is invoked by 'git commit', and can be bypassed 125with the `--no-verify` option. It takes a single parameter, the 126name of the file that holds the proposed commit log message. 127Exiting with a non-zero status causes the 'git commit' to 128abort. 129 130The hook is allowed to edit the message file in place, and can be used 131to normalize the message into some project standard format. It 132can also be used to refuse the commit after inspecting the message 133file. 134 135The default 'commit-msg' hook, when enabled, detects duplicate 136"Signed-off-by" lines, and aborts the commit if one is found. 137 138post-commit 139~~~~~~~~~~~ 140 141This hook is invoked by 'git commit'. It takes no parameters, and is 142invoked after a commit is made. 143 144This hook is meant primarily for notification, and cannot affect 145the outcome of 'git commit'. 146 147pre-rebase 148~~~~~~~~~~ 149 150This hook is called by 'git rebase' and can be used to prevent a 151branch from getting rebased. The hook may be called with one or 152two parameters. The first parameter is the upstream from which 153the series was forked. The second parameter is the branch being 154rebased, and is not set when rebasing the current branch. 155 156post-checkout 157~~~~~~~~~~~~~ 158 159This hook is invoked when a 'git checkout' is run after having updated the 160worktree. The hook is given three parameters: the ref of the previous HEAD, 161the ref of the new HEAD (which may or may not have changed), and a flag 162indicating whether the checkout was a branch checkout (changing branches, 163flag=1) or a file checkout (retrieving a file from the index, flag=0). 164This hook cannot affect the outcome of 'git checkout'. 165 166It is also run after 'git clone', unless the --no-checkout (-n) option is 167used. The first parameter given to the hook is the null-ref, the second the 168ref of the new HEAD and the flag is always 1. 169 170This hook can be used to perform repository validity checks, auto-display 171differences from the previous HEAD if different, or set working dir metadata 172properties. 173 174post-merge 175~~~~~~~~~~ 176 177This hook is invoked by 'git merge', which happens when a 'git pull' 178is done on a local repository. The hook takes a single parameter, a status 179flag specifying whether or not the merge being done was a squash merge. 180This hook cannot affect the outcome of 'git merge' and is not executed, 181if the merge failed due to conflicts. 182 183This hook can be used in conjunction with a corresponding pre-commit hook to 184save and restore any form of metadata associated with the working tree 185(e.g.: permissions/ownership, ACLS, etc). See contrib/hooks/setgitperms.perl 186for an example of how to do this. 187 188pre-push 189~~~~~~~~ 190 191This hook is called by 'git push' and can be used to prevent a push from taking 192place. The hook is called with two parameters which provide the name and 193location of the destination remote, if a named remote is not being used both 194values will be the same. 195 196Information about what is to be pushed is provided on the hook's standard 197input with lines of the form: 198 199 <local ref> SP <local sha1> SP <remote ref> SP <remote sha1> LF 200 201For instance, if the command +git push origin master:foreign+ were run the 202hook would receive a line like the following: 203 204 refs/heads/master 67890 refs/heads/foreign 12345 205 206although the full, 40-character SHA-1s would be supplied. If the foreign ref 207does not yet exist the `<remote SHA-1>` will be 40 `0`. If a ref is to be 208deleted, the `<local ref>` will be supplied as `(delete)` and the `<local 209SHA-1>` will be 40 `0`. If the local commit was specified by something other 210than a name which could be expanded (such as `HEAD~`, or a SHA-1) it will be 211supplied as it was originally given. 212 213If this hook exits with a non-zero status, 'git push' will abort without 214pushing anything. Information about why the push is rejected may be sent 215to the user by writing to standard error. 216 217[[pre-receive]] 218pre-receive 219~~~~~~~~~~~ 220 221This hook is invoked by 'git-receive-pack' on the remote repository, 222which happens when a 'git push' is done on a local repository. 223Just before starting to update refs on the remote repository, the 224pre-receive hook is invoked. Its exit status determines the success 225or failure of the update. 226 227This hook executes once for the receive operation. It takes no 228arguments, but for each ref to be updated it receives on standard 229input a line of the format: 230 231 <old-value> SP <new-value> SP <ref-name> LF 232 233where `<old-value>` is the old object name stored in the ref, 234`<new-value>` is the new object name to be stored in the ref and 235`<ref-name>` is the full name of the ref. 236When creating a new ref, `<old-value>` is 40 `0`. 237 238If the hook exits with non-zero status, none of the refs will be 239updated. If the hook exits with zero, updating of individual refs can 240still be prevented by the <<update,'update'>> hook. 241 242Both standard output and standard error output are forwarded to 243'git send-pack' on the other end, so you can simply `echo` messages 244for the user. 245 246[[update]] 247update 248~~~~~~ 249 250This hook is invoked by 'git-receive-pack' on the remote repository, 251which happens when a 'git push' is done on a local repository. 252Just before updating the ref on the remote repository, the update hook 253is invoked. Its exit status determines the success or failure of 254the ref update. 255 256The hook executes once for each ref to be updated, and takes 257three parameters: 258 259 - the name of the ref being updated, 260 - the old object name stored in the ref, 261 - and the new object name to be stored in the ref. 262 263A zero exit from the update hook allows the ref to be updated. 264Exiting with a non-zero status prevents 'git-receive-pack' 265from updating that ref. 266 267This hook can be used to prevent 'forced' update on certain refs by 268making sure that the object name is a commit object that is a 269descendant of the commit object named by the old object name. 270That is, to enforce a "fast-forward only" policy. 271 272It could also be used to log the old..new status. However, it 273does not know the entire set of branches, so it would end up 274firing one e-mail per ref when used naively, though. The 275<<post-receive,'post-receive'>> hook is more suited to that. 276 277In an environment that restricts the users' access only to git 278commands over the wire, this hook can be used to implement access 279control without relying on filesystem ownership and group 280membership. See linkgit:git-shell[1] for how you might use the login 281shell to restrict the user's access to only git commands. 282 283Both standard output and standard error output are forwarded to 284'git send-pack' on the other end, so you can simply `echo` messages 285for the user. 286 287The default 'update' hook, when enabled--and with 288`hooks.allowunannotated` config option unset or set to false--prevents 289unannotated tags to be pushed. 290 291[[post-receive]] 292post-receive 293~~~~~~~~~~~~ 294 295This hook is invoked by 'git-receive-pack' on the remote repository, 296which happens when a 'git push' is done on a local repository. 297It executes on the remote repository once after all the refs have 298been updated. 299 300This hook executes once for the receive operation. It takes no 301arguments, but gets the same information as the 302<<pre-receive,'pre-receive'>> 303hook does on its standard input. 304 305This hook does not affect the outcome of 'git-receive-pack', as it 306is called after the real work is done. 307 308This supersedes the <<post-update,'post-update'>> hook in that it gets 309both old and new values of all the refs in addition to their 310names. 311 312Both standard output and standard error output are forwarded to 313'git send-pack' on the other end, so you can simply `echo` messages 314for the user. 315 316The default 'post-receive' hook is empty, but there is 317a sample script `post-receive-email` provided in the `contrib/hooks` 318directory in Git distribution, which implements sending commit 319emails. 320 321[[post-update]] 322post-update 323~~~~~~~~~~~ 324 325This hook is invoked by 'git-receive-pack' on the remote repository, 326which happens when a 'git push' is done on a local repository. 327It executes on the remote repository once after all the refs have 328been updated. 329 330It takes a variable number of parameters, each of which is the 331name of ref that was actually updated. 332 333This hook is meant primarily for notification, and cannot affect 334the outcome of 'git-receive-pack'. 335 336The 'post-update' hook can tell what are the heads that were pushed, 337but it does not know what their original and updated values are, 338so it is a poor place to do log old..new. The 339<<post-receive,'post-receive'>> hook does get both original and 340updated values of the refs. You might consider it instead if you need 341them. 342 343When enabled, the default 'post-update' hook runs 344'git update-server-info' to keep the information used by dumb 345transports (e.g., HTTP) up-to-date. If you are publishing 346a Git repository that is accessible via HTTP, you should 347probably enable this hook. 348 349Both standard output and standard error output are forwarded to 350'git send-pack' on the other end, so you can simply `echo` messages 351for the user. 352 353push-to-checkout 354~~~~~~~~~~~~~~~~ 355 356This hook is invoked by 'git-receive-pack' on the remote repository, 357which happens when a 'git push' is done on a local repository, when 358the push tries to update the branch that is currently checked out 359and the `receive.denyCurrentBranch` configuration variable is set to 360`updateInstead`. Such a push by default is refused if the working 361tree and the index of the remote repository has any difference from 362the currently checked out commit; when both the working tree and the 363index match the current commit, they are updated to match the newly 364pushed tip of the branch. This hook is to be used to override the 365default behaviour. 366 367The hook receives the commit with which the tip of the current 368branch is going to be updated. It can exit with a non-zero status 369to refuse the push (when it does so, it must not modify the index or 370the working tree). Or it can make any necessary changes to the 371working tree and to the index to bring them to the desired state 372when the tip of the current branch is updated to the new commit, and 373exit with a zero status. 374 375For example, the hook can simply run `git read-tree -u -m HEAD "$1"` 376in order to emulate 'git fetch' that is run in the reverse direction 377with `git push`, as the two-tree form of `read-tree -u -m` is 378essentially the same as `git checkout` that switches branches while 379keeping the local changes in the working tree that do not interfere 380with the difference between the branches. 381 382 383pre-auto-gc 384~~~~~~~~~~~ 385 386This hook is invoked by 'git gc --auto'. It takes no parameter, and 387exiting with non-zero status from this script causes the 'git gc --auto' 388to abort. 389 390post-rewrite 391~~~~~~~~~~~~ 392 393This hook is invoked by commands that rewrite commits (`git commit 394--amend`, 'git-rebase'; currently 'git-filter-branch' does 'not' call 395it!). Its first argument denotes the command it was invoked by: 396currently one of `amend` or `rebase`. Further command-dependent 397arguments may be passed in the future. 398 399The hook receives a list of the rewritten commits on stdin, in the 400format 401 402 <old-sha1> SP <new-sha1> [ SP <extra-info> ] LF 403 404The 'extra-info' is again command-dependent. If it is empty, the 405preceding SP is also omitted. Currently, no commands pass any 406'extra-info'. 407 408The hook always runs after the automatic note copying (see 409"notes.rewrite.<command>" in linkgit:git-config[1]) has happened, and 410thus has access to these notes. 411 412The following command-specific comments apply: 413 414rebase:: 415 For the 'squash' and 'fixup' operation, all commits that were 416 squashed are listed as being rewritten to the squashed commit. 417 This means that there will be several lines sharing the same 418 'new-sha1'. 419+ 420The commits are guaranteed to be listed in the order that they were 421processed by rebase. 422 423 424GIT 425--- 426Part of the linkgit:git[1] suite