Perl Style: Avoid Testing eof

Don't use this: (deadlock)

    while (!eof(STDIN)) {
        statements;
    }

Use this instead:

    while (<STDIN>) {
        statements;
    }

Prompting while not eof can be a hassle. Try this:

   $on_a_tty = -t STDIN && -t STDOUT;
   sub prompt { print "yes? " if $on_a_tty }
   for ( prompt(); <STDIN>; prompt() ) {
        statements;
   }