monitoring resident memory of a process

[grover mitchell]

I am trying to monitor the resident memory size of some apache processes to
find out what the memory footprint is like. I was planning on using the perl
Proc::ProcessTable module, but it seems to be lacking information:

uid: 0
gid: 0
pid: 78297
ppid: 78296
pgrp: 78297
sess: 78297
flags: sldr
utime: 10.000000
stime: 12.000000
time: 22.000000
wchan: select
start: 1129576848.000000
euid: 0
egid: 0
fname: apache
state: select
ttydev:
ttynum: -1
cmndline: /usr/local/sbin/apache
priority: 0


If I run the same script on a linux box, I get a table field called rss and
size, which is exactly what I am looking for here. The system is FreeBSD
4.10.

Any pointers would be great. Thanks!