I often add cases of test data after __END__ or __DATA__ in scripts
that use while(<>) loops --- and I used to always switch
between <> and <DATA> for testing purposes
(and usually forgot to switch back when done). I recall being quite happy
a few years back when I realized ("Doh!") I could just leave the bare diamond
op and run the script on the test data via
perl -w < script.pl. Actually, I mostly test within the
editor by sending the buffer to a filter of perl -w
with output directed to another buffer, but its the same thing.