my $first;
my $last;

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

   while (<$fh>) {
      $first = $_ if not defined $first;
      $last  = $_;
   }
}

##</code><code>##

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();
}

##</code><code>##

my $first;
my $last;

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

   ($first, $last) = (<$fh>)[0, -1];
}