ipcalc for OS X?

[Gretchen Hayman]

Howdy,

Does anyone know of any equivalent programs to ipcalc for Mac OS X?  
Fink doesn't have ipcalc listed (or such that I can find it) and my 
googling hasn't turned up a nice CLI replacement for OS X, so I thought 
I would ask the crowd for recommendations.  (CLI much preferred over 
GUI apps, btw.)  I have ipcalc available on my linux systems and there 
are some web-based tools, but I'd like something for OS X that I can 
use if I don't have access to my linux boxen or WWW access.  Of course, 
what I really want to hear is that "it's in there" in OS X, just named 
stupidly so that's hard to find.  ^_^

Many thanks for any suggestions.

gretchen