use strict;
use Tie::File;

my $f = shift;
my $l = shift -1;

tie my @f => 'Tie::File' => $f;
print "$l: $f[$l]";

##</code><code>##

perl -w gfarhat.pl testfile.txt 1
perl -w gfarhat.pl testfile.txt 2
...
perl -w gfarhat.pl testfile.txt 9998

##</code><code>##

perl -nle 'BEGIN{$l=pop}print if $.==$l' testfile.txt 1