Is there a way to find out how much memory my ruby app is using?

Is there a way to find out how much memory my ruby app is using? I am
on:
$ ruby --version
ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]

Constraint: Without recompile of ruby.

ruby-prof has already been investigated and nixed due to the need for
recompiling.

Thank you in advance,

Charles

Thank you in advance,

Charles

How about just using a linux system tool, like top perhaps? -