use strict;
use warnings;
use CGI;
use CGI::Carp qw(fatalsToBrowser);

my $cgi = CGI->new;
my %form = $cgi->Vars;

print $cgi->header;

my $file = "data.bin";
open (my $IN, "<", $file) or die "$0: Can't open input file $file: $!\n";

my %Params;

while (<$IN>) {
    chomp;
    if ($_ =~ /^\@Params_/) {
        my ($key, $value) = split(/=/, $_);
        $Params{$key} = $value;
		#print "$key=$value\n";
    }
}
close($IN);

open (my $FILE, ">", $file) or die "$0: Can't open input file $file: $!\n";  #Clear the file

print $FILE "\@Params_fname=$form{'fname'}\n";
my $counter = $Params{"\@Params_visitor"} + 1;
print $FILE "\@Params_visitor=$counter";

close($FILE);

print	$cgi->start_html('Hello World'),
	$cgi->p("Welcome $form{fname}!"),
	$cgi->p("You are visitor # $counter"),
	$cgi->end_html;

exit;