my $buildings={};  #set up a hash reference
while (my $line = <MYFILE>) {
   #... parse line
  $buildings->{$bldg_name}{'name'} = $bldg_name;
  $buildings->{$bldg_name}{'number'} = $vlan_number;
   #... and so on
}
# ... more stuff
print_hash($buildings);