use strict; 
use warnings; 

use Benchmark;
use Tie::File; 
use File::ReadBackwards; 

my $file = "bench.txt"; #60 MB

timethese
(
    5, 
    {
        'bw'   => sub
        {
            my $bw = File::ReadBackwards->new( $file ) or die "can't read '$_[0]' $!" ; 

            my @lines; 

            $lines[0] = $bw->readline; 

            if ( $lines[0] =~ /;738409000;/ ) 
            { 
                for (1..9) 
                { 
                    $lines[$_] = $bw->readline; 
                }
            } 

            @lines = reverse @lines;

            return \@lines;
        },


        'tied' => sub 
        {
            my @array; 
            my @lines;

            tie @array, 'Tie::File', $file or die $!; 
            if ( $array[-1] =~ /;738409000;/ ) 
            {
                for (1..10)
                {
                    $lines[$_-1] = $array[(11-$_)*-1] . "\n";
                }
            }

            return \@lines;
        }

    }
);

##</code><code>##

Benchmark: timing 5 iterations of bw, tied...
        bw:  0 wallclock secs ( 0.00 usr +  0.00 sys =  0.00 CPU)
            (warning: too few iterations for a reliable count)
      tied: 69 wallclock secs (50.44 usr + 14.67 sys = 65.11 CPU) @  0.08/s (n=5)

##</code><code>##

Benchmark: timing 1500 iterations of bw, tied...
        bw:  1 wallclock secs ( 0.36 usr +  0.30 sys =  0.66 CPU) @ 2283.11/s (n=1500)
      tied:  5 wallclock secs ( 2.05 usr +  3.31 sys =  5.36 CPU) @ 279.90/s (n=1500)