use strict;
use warnings;
use Data::Dumper;

my %hash;

while (<DATA>) {
	chomp;
	my ( $url, $subject, $date ) = split /\t/;
	$hash{$url}->[0] //= $subject;
	push @{ $hash{$url}[1] }, $date;
}

local $" = ', ';
print "Url|Title|Date(s)|Count\n";
for my $key ( keys %hash ) {
	print "$key|$hash{$key}->[0]|@{ $hash{$key}[1] }|"
	  . scalar @{ $hash{$key}[1] } . "\n";
}

print "\n", Dumper \%hash;

__DATA__
http://www.perl.com	Perl	01/05/10 7:44PM
http://www.google.com/page?id=blah	Google Search results for blah	01/05/10 7:44PM
http://www.google.com/page?id=blah	Google Search results for blah	05/10/12 8:12AM
http://www.perl.com	Perl	01/05/10 7:42AM
http://www.perl.com	Perl	01/10/10 9:44PMM

##</code><code>##

Url|Title|Date(s)|Count
http://www.google.com/page?id=blah|Google Search results for blah|01/05/10 7:44PM, 05/10/12 8:12AM|2
http://www.perl.com|Perl|01/05/10 7:44PM, 01/05/10 7:42AM, 01/10/10 9:44PM|3

$VAR1 = {
          'http://www.google.com/page?id=blah' => [
                                                    'Google Search results for blah',
                                                    [
                                                      '01/05/10 7:44PM',
                                                      '05/10/12 8:12AM'
                                                    ]
                                                  ],
          'http://www.perl.com' => [
                                     'Perl',
                                     [
                                       '01/05/10 7:44PM',
                                       '01/05/10 7:42AM',
                                       '01/10/10 9:44PM'
                                     ]
                                   ]
        };