.... or issue a warning if -a was omitted but -F given:

13:30:52 [DataCollector]: ruby --version
ruby 1.8.1 (2003-12-25) [i386-cygwin]
13:31:03 [DataCollector]: echo "foo bar" | ruby -n -F\\s+ -e 'p $F'
nil
13:31:27 [DataCollector]: echo "foo bar" | ruby -n -aF\\s+ -e 'p $F'
["foo", "bar"]

Would come handy in finding some errors faster.

Kind regards

    robert