Christian Weiske has a problem he hopes you can help with - he's trying to get the PHP_Codesniffer tool integrated into his git workflow (well, the workflow of his team) as an automatic process that runs on commit. Unfortunately he's having some issues.

At work, we used a SVN server and enforced our project coding standard with a pre-commit hook on the server that ran PHP_CodeSniffer. Whenever a developer tried to commit some code that does not match the standard, he got it rejected. [...] The only way to enforce the standard is a pre-receive hook on our central Git repository server that all devs push to. Just installing the SVN hook on it isn't the solution, though.

Because of how git handles commits (possibly multiple in one push) the usual methods won't work. Other tricky things like file renaming and allowing for legacy code check-ins are also needed. He's posted the question on StackOverflow too, but no one's come up with a good answer yet (at the time of this post).