my $packed;
my $n =1000000-1;
my $offset = $n*4; 
my $success = shmread($id, $packed, $offset, 4)

##</code><code>##

use warnings;
use strict;
use IPC::SysV qw(IPC_PRIVATE IPC_RMID S_IRUSR S_IWUSR);

open(my $idx, "<", "$ARGV[0].idx") || die "cannot open data file\n $!";
my $idx_size = (split(' ',`wc -c $ARGV[0].idx`))[0];

my $idx_id = shmget(IPC_PRIVATE , $idx_size, S_IRUSR | S_IWUSR) || die "shmfet $!";
my $offset = 0;
foreach my $i (0..$idx_size/1000000) {
	my $n="";
	read($idx,$n,1000000);
	shmwrite($idx_id, $n, $offset, 1000000)  || die "shmwrite: $!";
	$offset +=1000000;
}

shmctl($idx_id, IPC_RMID, 0)        || die "shmctl: $!";

close $idx;

exit;


##</code><code>##

$ ipcs -m

##</code><code>##

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status     
0x00000000 8454205    valerio    600        4294967296 0              


##</code><code>##

 
$ perl -V:archname 
archname='x86_64-linux-gnu-thread-multi';