#! perl -slw
use strict;
use Data::Dumper;
##.............................V third parameter
my %hash = map{ split ',', $_, 2 } <DATA>;

print Dumper \%hash;

__DATA__
a name, an address, with commas,
another name, and another address, also with commas
and a third name, and address
fourth name, fourth address


##</code><code>##

C:\test>junk4
$VAR1 = {
          'and a third name' => ' and address
',
          'a name' => ' an address, with commas,
',
          'fourth name' => ' fourth address
',
          'another name' => ' and another address, also with commas
'
        };