mercurial hg POST to remote server with php

I have an account at bitbucket, here is what i want to achieve.

ME --push--> bitbucket <开发者_StackOverflow中文版;--post--> server

server to bitbucket is fine.

I try to setup the POST URL like this

<?php `hg pull -u`; 

in my server. Is this the correct way? i try to apply the back tick to execute the command.

I would suggest doing this with system() or exec(), simply because that's the standard operation procedure.