&read_csv;

sub read_csv {
   my @csv_lines = ('begin,middle,end'."\n",
                    '"This is a ""test""",middle,end'."\n",
                    '"""test"""", asd",middle,end'."\n",
                    '""","""",""",","",",end'."\n",
                    '"Multi-'."\n",
                    'line",middle,end'."\n");
   
   my $prev_line;
   foreach my $line (@csv_lines) {  # Normally, this would be a while(my $line = <CSV>) loop      
      print "CSVL: $line";
      $line =~ s/[\0\r]//g;
      $line = $prev_line.$line;
      
      # Parse quoted stuff
		while ($line =~ /(?<!\")(\")((?:\"\"|[^\"]+)+?)(\"|\n)(?!\")/gcs) {
			my ($endpos, $starter, $token, $ender) = (pos($line), $1, $2, $3);
			my $oldlen = length($starter.$token.$ender);
			my $startpos = $endpos - $oldlen;

			print "Token: $token ==> ";

			$token =~ s/\"\"/\0QUOTE\0/g;
			$token =~ s/,/\0COMMA\0/g;
			$token =~ s/\n/\0NEWLINE\0/g;
			$ender =~ s/\n/\0NEWLINE\0/g;

			print "$token\n";      

			substr($line, $startpos, $oldlen, ($starter.$token.$ender));
			pos($line) = $endpos + (length($starter.$token.$ender) - $oldlen);
			print "Line: $line\n";
		}

      # Runaway multi-line; grab the next line and try it again
      if ($line =~ /\0NEWLINE\0$/) {
         $prev_line = $line;
         next;
      }
      undef $prev_line;
      
      $line =~ s/[\"\n]//g;  # Remove non-data
      
      # Re-translate masked characters
      my @values = split(/,/, $line);
      foreach $value (@values) {
         $value =~ s/\0QUOTE\0/\"/g;
         $value =~ s/\0COMMA\0/\,/g;
         #$value =~ s/\0NEWLINE\0/\n/g;         
         $value =~ s/\0NEWLINE\0/\\n/g;  # for testing, use literal '\n'
      }
      
      print "Values: ".join(' | ', @values)."\n";
   }
}