#!/usr/local/bin/perl

### this script is not 100% effective because most browsers will cache the picture.gif used to count.
### sending an expires header might solve it, but it does give a fairly accurate count of unique visitors
### since it only counts each person once then the .gif is cached

&ReadParse;
&GetName("\t","/home/kevin/public_html/kstats");
&ServeImage("/home/kevin/public_html/dot.gif");


sub GetName {
	my($delimiter,$logfile) = @_;
	$logfile ||= "./logfile.txt";
	$delimiter ||= "\t";

	my $page = $in{'page'} || $ENV{'REQUEST_URI'};
	my $ip = $ENV{'REMOTE_ADDR'};
	my $ref = $ENV{'HTTP_REFERER'};
	my $agent = $ENV{'HTTP_USER_AGENT'};
	my $user = $ENV{'HTTP_FROM'};

	open(WRITINGNAME,">>$logfile");
	flock(WRITINGNAME, 2);	
	
	my($date) = scalar(localtime(time));
	
	my $headers = join ("$delimiter", ("DATE","PAGE VIEWED","REFERRER","IP ADDRESS","BROWSER/AGENT") );
	my $fields = join ("$delimiter", ($date,$page,$ref,$ip,$agent) );

	print WRITINGNAME "$headers\n" if (-s $logfile < 4);
	print WRITINGNAME "$fields\n";
	
	flock(WRITINGNAME, 8);
	close WRITINGNAME;

}






###########################################
##  ServeImage - sends image out to page
###########################################
sub ServeImage{
 		my ($image_name) = @_;
		$image_name ||= "pixel.gif";
		
        print "Content-Type:image/gif\n\n";
 
        open(IMAGE,"$image_name");
        $\ = 0;
        print (<IMAGE>);
        close IMAGE;
}
 
###########################################
##  ReadCookie - reads cookie info
###########################################
sub ReadCookie
{
		my($cdelimit) = @_;
		$cdelimit ||= "::";
		
        @read_cookie = split(/;/,$ENV{HTTP_COOKIE});
        @cookie = split(/$cdelimit/,$read_cookie[0]);
        foreach $cookie (@cookie){
                ($key, $val)=split(/=/,$cookie);
                $key =~ s/ //g;
                $cookie{$key}=$val;
        }
}


sub ReadParse {
   local(*in) = @_ if @_;
   
   local ($i, $loc, $key, $val);

   # Read in text
   if ($ENV{'REQUEST_METHOD'} eq "GET") {
      $in = $ENV{'QUERY_STRING'};
   }
   elsif ($ENV{'REQUEST_METHOD'} eq "POST") {
      read(STDIN, $in, $ENV{'CONTENT_LENGTH'});
   }

   @in = split(/&/, $in);
   
   foreach $i (0..$#in) {
      # Convert plus's to spaces
      $in[$i] =~ s/\+/ /g;

      # Split into key and value (split on the first "=")
      ($key, $val) = split(/=/, $in[$i],2);

      # Convert %XX from hex numbers to alphanumeric
      $key =~ s/%(..)/pack("c", hex($1))/ge;
      $val =~ s/%(..)/pack("c", hex($1))/ge;

      # Associate key and value
      $in{$key} .= "\0" if (defined ($in{$key}));
      $in{$key} .= $val;
   }         
      
   return 1;
   
}