physical RAM

[Frank D. Greco CIS Adj. Prof.]

Recently I asked a question relating to RAM size on a Sun.  I apologize
for being vague.  I must've received 10 answers with the obvious, telling
me to watch the screen while I'm booting or using "eeprom memsize".  What
I had meant to ask was how does one find out *dynamically* how much RAM is
currently available for application programs?  That is, I need a
programmatic method of finding out physical RAM usage.  I am building a
tool a la perfmeter that indicates physical RAM usage.  I'm sure there is
some info kept in the kernel on overall RAM usage, I just don't know where
to look.  Someone had told me that the program "top" shows this
information.  If someone can verify this fact and point me in the correct
direction to the src to top, I would appreciate it very much.

Thanks all,
Frank G.