#! perl -sw
use strict;
use Data::Dump qw[ pp ];
use Time::HiRes qw[ time ];

$|++;

our $O //= 3;

my @AoA; $#AoA = 10 ** $O;
$AoA[ $_ ] = [ 1 .. 1+rand 200 ] for 0 .. $#AoA;

pp \@AoA if $O <= 2;

my $start = time;
open O, '>:raw', 'junk26.bin' or die $1;
for ( 0 .. $#AoA ) {
    printf O pack 'V/A*', pack 'V*', @{ $AoA[ $_ ] }; ## switched printf to print
}
close O;
printf "Store took %.6f secs\n", time() - $start;
@AoA = ();

$start = time;

open I, '<:raw', 'junk26.bin' or die $!;
for ( 0 .. 10 ** $O ) {
    read( I, my $n, 4 );
    read( I, my $buf, unpack 'V', $n );
    $AoA[ $_ ] = [ unpack 'V*', $buf ];
}
close I;
printf "Retrieve took %.6f secs\n", time() - $start;

pp \@AoA if $O <= 2;

__END__
C:\test>junk26 -O=6
Store took 169.778000 secs
Retrieve took 170.926000 secs