open(HOSTDB,"hostdb") or die "cannot open hostdb"; 
                                      # open hosts one time only.
my @hosts;                           # array to hold the hosts.
while(<HOSTDB>){
	push @hosts, chomp($_);
}

# using scalar on an array will give you the number of elements
print "number of records - ", scalar @hosts, "\n";
close(HOSTDB);

# instead of counting and selecting the hosts, use perl's foreach
# to loop inside the @hosts array

foreach my $host (@hosts){
	
	print "------host.$host--------\n";
		 
	for my $field (split /\n/, $host ) {
	   print "Field contains: '$field'\n";
	}
}