package IPC::SharedMem;

use IPC::SysV qw(IPC_STAT IPC_RMID shmat shmdt memread memwrite);
use strict;
use vars qw($VERSION);
use Carp;

$VERSION = do { my @r = '$Snapshot: /IPC-SysV/2.01 $' =~ /(\d+\.\d+(?:_\d+)?)/; @r ? $r[0] : '9.99' };
$VERSION = eval $VERSION;

# Figure out if we have support for native sized types
my $N = do { my $foo = eval { pack "L!", 0 }; $@ ? '' : '!' };

{
    package IPC::SharedMem::stat;

    use Class::Struct qw(struct);

    struct 'IPC::SharedMem::stat' => [
	uid	=> '$',
	gid	=> '$',
	cuid	=> '$',
	cgid	=> '$',
	mode	=> '$',
	segsz	=> '$',
	lpid	=> '$',
	cpid	=> '$',
	nattch	=> '$',
	atime	=> '$',
	dtime	=> '$',
	ctime	=> '$',
    ];
}

sub new
{
  @_ == 4 or croak 'IPC::SharedMem->new(KEY, SIZE, FLAGS)';
  my($class, $key, $size, $flags) = @_;

  my $id = shmget $key, $size, $flags;

  return undef unless defined $id;

  bless { _id => $id, _addr => undef, _isrm => 0 }, $class
}

sub id
{
  my $self = shift;
  $self->{_id};
}

sub addr
{
  my $self = shift;
  $self->{_addr};
}

sub stat
{
  my $self = shift;
  my $data = '';
  shmctl $self->id, IPC_STAT, $data or return undef;
  IPC::SharedMem::stat->new->unpack($data);
}