How to execute a command right after a fetch or pull command in git?

git ghc githooks
fuz picture fuz · Apr 11, 2011 · Viewed 29.6k times · Source

I cloned the GHC (Glasgow Haskell Compiler) repository. In order to build the compiler, you need several libraries, all of them are available as git repositories too. In order to ease ones live, the GHC hackers included a script sync-all that, when executed, updates all the dependent repositories.

Now to my question: How can I make git execute ./sync-all pull after I did a git pull automatically? I heard something about using hooks, but I don't really know, what I have to do.

Answer

VonC picture VonC · Apr 11, 2011

If you need to execute a script after a git pull on the client side (your machine), then a there is no reliable solution.

The post-merge client-side hook (mentioned here) won't be triggered by every pull (for instance, not in a pull rebase, not in case of fast-forward merge)

So an alias wrapping both commands remains a possible workaround.

Original answer (2011)

If you need that on the server side, where you would checkout the bare repo and pull from a working tree (on the server) after each push to a bare repo (on the server):

A post-receive or post-update hook is generally used for this kind of task, executed after each push.
The difference between the post-receive and post-update hooks is in the arguments: a post-receive will get both the old and the new values of all the refs in addition to their names.

The missing piece is: where that hook executes itself?

The blog post "Missing git hooks documentation" from (a great) SO contributor Mark Longair sheds some light on this:

the current working directory will be the git directory.

  • So, if this is a bare repository called “/src/git/test.git/”, that will be the current working directory – if this is a non-bare repository and the top level of the working tree is “/home/mark/test/” then the current working directory will be “/home/mark/test/.git/”

Chris Johnsen details in his SO answer: "If –-git-dir or GIT_DIR are specified but none of -–work-tree, GIT_WORK_TREE and core.worktree is specified, the current working directory is regarded as the top directory of your working tree."

In other words, your working tree will also be the current directory (the “.git” directory), which almost certainly isn’t what you want.

Make sure your hook/post-receive script, once created and made executable, sets the GIT_WORK_TREE at the right path, in order for your ./sync-all pull to be executed in the right directory (i.e. not "xxx.git" one).

Related questions

How do I undo the most recent local commits in Git?

I accidentally committed the wrong files to Git, but didn't push the commit to the server yet. How can I undo those commits from the local repository?

Read More
How do I delete a Git branch locally and remotely?

I want to delete a branch both locally and remotely. Failed Attempts to Delete a Remote Branch $ git branch -d remotes/origin/bugfix error: branch 'remotes/origin/bugfix' not found. $ git branch -d origin/bugfix error: branch 'origin/bugfix' not …

Read More
How do I revert a Git repository to a previous commit?

How do I revert from my current state to a snapshot made on a certain commit? If I do git log, then I get the following output: $ git log commit a867b4af366350be2e7c21b8de9cc6504678a61…

Read More