use File::Basename;

#list of filenames to normalize
my @index_file_names=qw(index.html index.htm index.php index.asp index.cgi);


sub normalize_url {
    my $old_url = $_[0];
    chomp($old_url);
    #saves name at the end 
    my $filename=basename($old_url);

    if (grep {$_ eq $filename} @index_file_names) {
	#saves the directory part
	my $normalized_url=dirname($old_url);
	$normalized_url;
    }else{
        #don't need to normalize url
	$old_url; 
    }
}