Hello dear Monks, I would like to ask a simple question to your unlimited Monk knowledge. In recent days I've been reading Shared Memory modules code but all of the sudden I encountered some 'unpack' syntax that was very unfamiliar to me:

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);
}

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What I can not figure out is the line of code that has 'unpack' in it. If any Monk could share his/her wisdom to this apprentice would be great. My initial guess is that somehow 'unpack' is a method of the class IPC::SharedMem::stat but I may also think that it is actually the core unpack function that somehow is being used as a method

In reply to IPC::SharedMem::stat using Class::Struct by sprinter

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