#!/usr/bin/perl
# script to count accesses to top level directory
# and then redirect to a known place in the web tree
# data is stored in a dbm file keyed by path and number of
# accesses.
use strict;
use Fcntl;
use NDBM_File;
my $dbm = "/mount/www/logs/eventaccess";
my $dbmlock = "/mount/www/logs/eventaccess.lock";
exit(0) unless(defined($ENV{SCRIPT_NAME}) and defined($ENV{SERVER_NAME}));
my $path = $ENV{SCRIPT_NAME};
$path =~ s,/+,/,g;
$path =~ s/\/index.html$//;
# the toplevel name in the path is assumed to be the
# conference name. 
my @pathlist = split /\//,$path;
my $event = $pathlist[0];
# the path may start with /
$event = $pathlist[1] if ($event eq "");
my $server = $ENV{SERVER_NAME};
my $http = "http";
if ($server =~ m/db.usenix.org/) {
	$http = "https";
}
# lock things
sysopen LOCKF, $dbmlock,&O_CREAT|&O_RDWR, 0664;
flock LOCKF, 0x2;
my %db;
tie %db, 'NDBM_File', $dbm, &O_RDWR|&O_CREAT, 0777;
my $ti = time();
my @line = ();
# line is count:starttime:thistime
if (defined($db{$path})) {
 	@line = split /:/, $db{$path};
	$line[0]++;
	$line[2] = $ti;
} else {
	$line[0] = 1;
	$line[1] = $ti;
	$line[2] = $ti;
}
$db{$path} = join(":", @line);
untie %db;
flock LOCKF, 0x8;
close LOCKF;
print "Location: $https://$server/events/$event/index.html\n\n";
exit 0;