use Tie::File;		# Record separator per default = $/
use Fcntl 'O_RDONLY';   # open in read-only mode
my ($sep1, $sep2) = ($ENV{'windir'})   # determine OS
      ? ("\r\n", "\n") : ("\n", "\r\n");
my $file = shift @ARGV;
tie my @array, 'Tie::File', $file, mode => O_RDONLY,
      memory => 0, recsep => $sep1 or die $!;
my $n_recs = @array;	# how many records are in the file?
unless ($n_recs > 1) {
   untie @array;
   tie @array, 'Tie::File', $file, mode => O_RDONLY,
         memory => 0, recsep => $sep2 or die $!;
   $n_recs = @array;
   print join ("~SEP~", @array);
   die "Found only one array element\n" unless $n_recs > 1;
}