#!/usr/bin/perl
require "cgi-lib.pl";
require "incrementCounter.pl";
&ReadParse;
$visitors="visitors.db";
$counterfile="counterfile.txt";
$tyme=time;
$username=$in{'username'};
if (length($username)<=0)
{
$counter=&incrementCounter($counterfile);
$username="$counter";
}
## need to lock $visitors file right here
$lockfile=$visitors."lock";
## if counter file is locked wait.
while(-e $lockfile)
{
sleep(1);
}
##lock visitor file
open(FILE,">".$lockfile);
close(FILE);
dbmopen %Aliases,$visitors,0666;
while(($key,$value)= each %Aliases)
{
$diff=$tyme-$Aliases{$key};
if ($diff>36)
{
delete $Aliases{$key};
}
}
$Aliases{$username}=$tyme;
dbmclose(%Aliases);
dbmopen %Aliases,$visitors,0666;
while(($key,$value)= each %Aliases)
{
$data.=",$key";
}
dbmclose(%Aliases);
##unlock counter file
unlink($lockfile);
## print page
print &PrintHeader;
print <<"_P_A_G_E_";
$data