use File::ReadBackwards ();

my $first;
my $last;

{
   open(my $fh, '<', 'file')
      or die("Unable to open input file: $!\n");

   $first = <$fh>;
}

{
   my $fh = File::ReadBackwards->new('file')
      or die("Unable to open input file: $!\n");

   $last = $fh->readline();
}