#!/usr/bin/perl
use warnings;
use strict;
use Sys::Mmap;

 my $mmap;
 #open( FH, '<:mmap',"$0" ) 
  open( FH, "< $0" )
      or die "Couldn't open 'file': $!\n";

  my $smaddress =  mmap( $mmap, 0, PROT_READ, MAP_SHARED, FH )
                  or die "mmap error: $!\n";


print "$smaddress\n\n$mmap\n\nCheck ipcs -m and hit enter\n\n";

<>;

munmap($mmap) or die "mmunmap error: $!\n";
close(FH) or die "Couldn't close 'file': $!\n";