limit devs on the length of a function

limit devs on the length of a function

We are working in a GIANT project, and as with giant projects some
classes, funcitons, files tend to get, weeelll lets say giant (40k lines
of code in a single file, ifs wich can span over 5k lines of code).
I am looking for a way to annoy the develeopers to the point they split
their "function if fooo" when a file gets to much out of hand.
i need 2 solutions limit the developer so he cant make a function in php
wich is bigger then 2k lines of code. Other one is i need to limit the
lenth of a file to a reasonable size.
We are working with zend and extjs.