Git diff branch - filter by extension?

Question

I'm diffing 2 branches with git diff master..branch2 and diff shows me html, css, php files, etc. I'd like to only view php files here, but git diff master..branch2 -- '*.php' returns nothing. How do I actually filter it?

Answer 1

Yeah this was an issue with the version of git - Centos 6.5 has 1.7.1 in current yum. I've updated it to 1.9.4 manually and it all worked!