#!/usr/bin/perl

use Tie::File;
use strict;
use warnings;

my $filename = "dbfile.txt";
tie my @array, 'Tie::File', $filename or die "can't open $filename: $!";

$array[13] = 'blah';            # line 13 of the file is now 'blah'
print $array[42];               # display line 42 of the file

__END__