#! perl -slw
use strict;
use Math::Random::MT qw[ rand ];

open O, '>:raw', 'data/650MB.bin';
print O unpack 'B44', pack'NN', rand( 2**32 ), rand( 2**32 ) for 1 .. 15e6;
close O;

open O, '>:raw', 'data/600.bin';
print O unpack 'B7', pack 'C', rand(256)  for 1 .. 600;
close O;

##</code><code>##

#! perl -slw
use strict;

my $data;
open my $bigFH, '<:raw', 'data/650MB.bin' or die $!;
sysread( $bigFH, $data, -s( 'data/650MB.bin' ) );
close $bigFH;

open my $smallFH, '<', 'data/600.bin' or die $!;
while( <$smallFH> ) {
    print STDERR "\n$. ";
    chomp;
    my $name = "data/$_.posns";
    next if -e $name;
    open O, '>', $name or die $!;
    print STDERR "File: '$name' opened";
    my $p = 0;
    while( $p = 1+index( $data, $_, $p ) ) {
        print O $p;
    }
    close O;
}
close $smallFH;