where is php extensions?

[=?GB2312?B?sKLOxA==?=]

hello,all.

my os is FreeBSD 6.0 Beta.

i use ports to install php and apache.right now everything is working
fine.but i edit php.ini ,need some extensions,and i don't know wher e
it is. there is a directory named "build" under /usr/local/lib/php/ .

how to add more php extensions?

-- 
              Best Wishes,
                                    Yours Arvan