#!/perl/bin/perl
#/usr/local/bin/perl
# Use as <img src="/cgi-bin/tracker.pl?who=trackertest"></a><br>
#  the 'who' opens a unique log file, which should exist beforehand
# logfile must not be in cgi-bin for some servers to handle it
# properly
my $picfile = "smiley.gif";
my $date = gmtime();

@pairs = split(/&/, $ENV{QUERY_STRING});
foreach $pair (@pairs) {
 ($name, $value) = split(/=/, $pair);
 $name =~ tr/+/ /;
 $name =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
 $value =~ tr/+/ /;
 $value =~ tr/\r\n|//d;
 $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
 $input{$name} = $value;
 }

my $trackerlog="tracker.log";
if (exists $input{'who'}) {
   $trackerlog= "../logs/" . $input{'who'} . ".log" ;  #thats the log file
   delete $input{'who'};                 #don't need it anymore
}
if (exists $input{'pic'}) {
   $picfile = "../images/" . $input{'pic'};            #change the graphic
   delete $input{'pic'};                 #don't need it anymore
}

	if (open(LOGFILE,">>$trackerlog")) { #Note: silent on failure
#      while ( not flock(LOGFILE,2)) {sleep(1);}  
      print LOGFILE "$date|$ENV{'REMOTE_HOST'}|$ENV{'HTTP_REFERER'}|$ENV{'HTTP_USER_AGENT'}";
      while (($key,$val)=each %input) {
         print LOGFILE "|$key=$val";
	  }
      print LOGFILE "\n";
	  close (LOGFILE);
    }
     else {$picfile="none";}
binmode( STDOUT );
print "Content-type:image/gif\n\n";
open(PIC,"+<$picfile") or die "can't find $picfile\n";
binmode PIC;
@picdata = <PIC>;
print @picdata;
close PIC;
1