A simple way to serve up fortunes on a webpage.

fortune.pl

#!/usr/bin/perl -w

# This script picks a fortune out of a fortune file and prints it.
# We start by counting the number of fortune separators there are in the file 
# '%'.  Pick a random number from zero to the number of separators found.
# Then rewind the file and count out that many separators.
# Next we load the upcoming fortune into a string, making sure not
# load the trailing separator, if there is one.  Then print.

# This script  is optimized for memory usage.
# It will not inhale an entire fortune file.  Therefore this script is ideal
# for serving up fortunes from a very large file.

my $www_root = "/var/www/661.org";
my $file = "$www_root/fortune.txt";
my $number;
my $fortune;
my $target;


if (!open(F, $file)) {
        print "Oops.  Cannot open fortune file '$file'!\n";
        exit;
}

srand(time);

# Count the number of fortunes (or separators).
$number = 0;
while (<F>) { if (m/^%+$/ ) { $number++; } }

RESTART:

# Pick a random index.
$target = (rand(1000) * time) % ($number + 1);
$number = 0;

# Rewind.  Count separators until we get to the fortune we want.
# Then load up $fortune until the next separator or the fortune file ends.
seek F, 0, 0;
while (<F>) {
	if ($number > $target) { last; }
	if (m/^%$/) { $number++; }
	if ($number == $target && !(m/^%+$/)) {
		$fortune .= $_;
	}
}

# Two separators in a row and trailing separators will yield a null fortune.
# If that's what we got, try again.
if (!$fortune) { goto RESTART; }

print "Content-type: text/plain\n\n";
print $fortune;
exit;