In that case (and you may already have this worked out) if you are building one great big hash, the main code would look something like:

open HANDLE, 'testhash.txt' or die "Can't open: $!";
my %hash;
for my $data (<HANDLE>) {
   chomp $data;
   foreach my $pair (split /'/, $data) {
      next if $pair eq '';
      next if $pair =~ /^,$/;
      my ($key, $value) = split /,/, $pair;
      $hash{$key} = $value;
   }
}
close HANDLE;
# do stuff with entire hash here
[download]

Or if you are doing something with the hash line-by-line:

open HANDLE, 'testhash.txt' or die "Can't open: $!";
for my $data (<HANDLE>) {
   chomp $data;
   my %hash;
   foreach my $pair (split /'/, $data) {
      next if $pair eq '';
      next if $pair =~ /^,$/;
      my ($key, $value) = split /,/, $pair;
      $hash{$key} = $value;
   }
   # do interesting things with one-line %hash here
}
close HANDLE;
[download]