in reply to Re^2: opening many files
in thread opening many files

http://learn.perl.org/faq/perlfaq4.html#How-do-I-sort-an-array-by-anything-

http://perldoc.perl.org/perlfaq4.html#How-do-I-sort-an-array-by-%28anything%29%3f

Sorting ip addresses quickly

In Section Seekers of Perl Wisdom