http://www.perlmonks.org?node_id=178297
jdpindynet has asked for the wisdom of the Perl Monks concerning the following question:

Oh holy ones ... this knave is trying to use backticks repeatedly with a program that returns a variable number of lines. How can I tell how many lines I got?
my @lines = `findgsc $ra$sign$dec -rs 6 -p 2 -n 10 `; if ($#lines >= 3) { do stuff; } else { do other stuff }
Which seems to work fine, the first time around. What do the Monks think about using $#lines on the next time around? If the program returned 5 lines the first time, and only 2 the next, won't there be lines left over from the first time? How can I tell how many _additional_ lines I got back? Awaiting your wisdom. jdpindynet