Hi. Okay, would the maths folk like to offer a helpful explanation? a ---------- Forwarded message ---------- Question: How do I select a random line from a file? Here's an algorithm from the Camel Book: srand; rand($.) < 1 && ($line = $_) while <>; This has a significant advantage in space over reading the whole file in. A simple proof by induction is available upon request if you doubt its correctness. -- The contents of this message are part of the Perl FAQ: Please note that "I" below refers to FAQ authors, and *not* Jeff Yoak or Perl FAQ a Day. Where to get this document [the Perl FAQ] This document is posted regularly to comp.lang.perl.announce and several other related newsgroups. It is available in a variety of formats from CPAN in the /CPAN/doc/FAQs/FAQ/ directory, or on the web at http://www.perl.com/perl/faq/ . CREDITS When I first began the Perl FAQ in the late 80s, I never realized it would have grown to over a hundred pages, nor that Perl would ever become so popular and widespread. This document could not have been written without the tremendous help provided by Larry Wall and the rest of the Perl Porters. AUTHOR AND COPYRIGHT INFORMATION Copyright (c) 1997 Tom Christiansen and Nathan Torkington. All rights reserved. -- 162 ..Thread Next