regular expressions & testing

Is there an easy way to test a newly added field to a .procmailrc file?
Sorta like a sanity check on what's been written.

Secondly, are the regular expression used by procmail standard .. in such
that a person familiar with perl and shell scripts would be able to jump
right in or are there odd quirks to pay attention to?

Thanks,
--
Jeremy Dinsel                      (PGP key: finger 
dinselj(_at_)sighsy(_dot_)cup(_dot_)edu )
                                   (PGP key: http://sighsy.cup.edu/~dinselj)
   Cal U Math and Computer         (PGP use preferred)
   Science World Wide Web           
   System Administrator