Inotify! With Linux::Inotify2 for Perl and shell based stuff like inotifyd (and other language equivs), scripting those kinds of things to happen automatically on a Linux system becomes pretty easy; you can just have the commit stages (I presume, I've not used git myself yet) on file update detection. I often use it for clients who run Windows, connecting to Linux system running Samba. They drag a file into a specific shared directory, upon the fclose event my code kicks in, processes it, spits them back out the processed result. I don't have to write any kind of interface, they don't have to learn one, I love it, has the potential to be my hammer-for-everything though so don't be surprised if it's not helpful here!