From: Dirk Traulsen <dirk.traulsen@...>
Date: 2007-10-24T21:00:55+09:00
Subject: Re: format string for array question

Or you could use "zero-width positive lookahead"  /(?=)/ with -? for 
possible negative numbers:

s = "db file parallel -write         8816         391    -25.49"
p s.split(/\s+(?=-?\d)/)

#=> ["db file parallel -write", "8816", "391", "-25.49"]