open (DATA, "<data.txt") or die "Can't open file $!\n";
  @DATA = <DATA>;
  close (DATA);

  foreach $rec (@DATA) {
      chomp $rec;
      my @vars = split(/\s*,\s*/,$rec);
      # debug - you might want to join with '|' to see
      # whitespace in any vars
      print "VARS = " . join('|', @vars). "\n";
      # now insert into the hash
      $var_hash{$vars[2]} = 'whatever';
  }