print "$member can be found " . scalar(@{$family{$member}}) / ? . ": "

##</code><code>##

#!/usr/bin/perl
use Data::Dumper;          # only for teaching purpose
$Data::Dumper::Indent = 1; # dito :-)

while(<DATA>) {
    chop;
    my($familyname,$memberstring) = split /\s--\s/,$_;
    my @members = split /, /,$memberstring;
    # tell each member that it's got a new family
    foreach my $member(@members) {
        push(@{$family{$member}},$familyname);
    } 
} 
print Dumper(\%family); # show the data structure in %family
# now output a list of members with their families
foreach my $member(sort keys %family) {
    print "$member can be found " . scalar(@{$family{$member}}) . ": "
        . join(" ", @{$family{$member}}) . "\n";
} 

##</code><code>##

FLINTSTONES=BARNEY, FRED, WILMA
JETSONS=MAX, TONY, WILMA
SIMPSONS=LISA, BARNEY, WILMA, HOMER
ALCATRAZ=ELIJAH, MAX, WILMA

##</code><code>##

sub nice_list {
   return ''    if @_ == 0;
   return shift if @_ == 1;

   my $last = pop;
   return join(', ', @_) . " and $last";
}

my $line;
my @data;
my @family;
my @members;


foreach $line (@data){
@family = split ('=', $line);
@members = split (',', $family[1]);
my %is_eaten_by = (
   $family[0]  => [ (@members) ],
  );

foreach my $fruit (keys %is_eaten_by) {
   my $eaters = $is_eaten_by{$fruit};
   my $num_eaters = @$eaters;
   print("$num_eaters  ${fruit}: ",
         (@$eaters), "\n");
}
}

##</code><code>##

BARNEY can be found 2: FLINTSTONES SIMPSONS
FRED can be found 1: FLINTSTONES
WILMA can be found 4: FLINTSTONES JETSONS SIMPSONS ALCATRAZ
MAX can be found 2: JETSONS ALCATRAZ 
and so forth...