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# IPC::Msg.pm
#
# Copyright (c) 1997 Graham Barr <gbarr@pobox.com>. All rights reserved.
# This program is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
package IPC::Msg;
use IPC::SysV qw(IPC_STAT IPC_SET IPC_RMID);
use strict;
use vars qw($VERSION);
use Carp;
$VERSION = "1.00";
{
package IPC::Msg::stat;
use Class::Struct qw(struct);
struct 'IPC::Msg::stat' => [
uid => '$',
gid => '$',
cuid => '$',
cgid => '$',
mode => '$',
qnum => '$',
qbytes => '$',
lspid => '$',
lrpid => '$',
stime => '$',
rtime => '$',
ctime => '$',
];
}
sub new {
@_ == 3 || croak 'new IPC::Msg ( KEY , FLAGS )';
my $class = shift;
my $id = msgget($_[0],$_[1]);
defined($id)
? bless \$id, $class
: undef;
}
sub id {
my $self = shift;
$$self;
}
sub stat {
my $self = shift;
my $data = "";
msgctl($$self,IPC_STAT,$data) or
return undef;
IPC::Msg::stat->new->unpack($data);
}
sub set {
my $self = shift;
my $ds;
if(@_ == 1) {
$ds = shift;
}
else {
croak 'Bad arg count' if @_ % 2;
my %arg = @_;
my $ds = $self->stat
or return undef;
my($key,$val);
$ds->$key($val)
while(($key,$val) = each %arg);
}
msgctl($$self,IPC_SET,$ds->pack);
}
sub remove {
my $self = shift;
(msgctl($$self,IPC_RMID,0), undef $$self)[0];
}
sub rcv {
@_ <= 5 && @_ >= 3 or croak '$msg->rcv( BUF, LEN, TYPE, FLAGS )';
my $self = shift;
my $buf = "";
msgrcv($$self,$buf,$_[1],$_[2] || 0, $_[3] || 0) or
return;
my $type;
($type,$_[0]) = unpack("l! a*",$buf);
$type;
}
sub snd {
@_ <= 4 && @_ >= 3 or croak '$msg->snd( TYPE, BUF, FLAGS )';
my $self = shift;
msgsnd($$self,pack("l! a*",$_[0],$_[1]), $_[2] || 0);
}
1;
__END__
=head1 NAME
IPC::Msg - SysV Msg IPC object class
=head1 SYNOPSIS
use IPC::SysV qw(IPC_PRIVATE S_IRWXU);
use IPC::Msg;
$msg = new IPC::Msg(IPC_PRIVATE, S_IRWXU);
$msg->snd(pack("l! a*",$msgtype,$msg));
$msg->rcv($buf,256);
$ds = $msg->stat;
$msg->remove;
=head1 DESCRIPTION
A class providing an object based interface to SysV IPC message queues.
=head1 METHODS
=over 4
=item new ( KEY , FLAGS )
Creates a new message queue associated with C<KEY>. A new queue is
created if
=over 4
=item *
C<KEY> is equal to C<IPC_PRIVATE>
=item *
C<KEY> does not already have a message queue
associated with it, and C<I<FLAGS> & IPC_CREAT> is true.
=back
On creation of a new message queue C<FLAGS> is used to set the
permissions.
=item id
Returns the system message queue identifier.
=item rcv ( BUF, LEN [, TYPE [, FLAGS ]] )
Read a message from the queue. Returns the type of the message read.
See L<msgrcv>. The BUF becomes tainted.
=item remove
Remove and destroy the message queue from the system.
=item set ( STAT )
=item set ( NAME => VALUE [, NAME => VALUE ...] )
C<set> will set the following values of the C<stat> structure associated
with the message queue.
uid
gid
mode (oly the permission bits)
qbytes
C<set> accepts either a stat object, as returned by the C<stat> method,
or a list of I<name>-I<value> pairs.
=item snd ( TYPE, MSG [, FLAGS ] )
Place a message on the queue with the data from C<MSG> and with type C<TYPE>.
See L<msgsnd>.
=item stat
Returns an object of type C<IPC::Msg::stat> which is a sub-class of
C<Class::Struct>. It provides the following fields. For a description
of these fields see you system documentation.
uid
gid
cuid
cgid
mode
qnum
qbytes
lspid
lrpid
stime
rtime
ctime
=back
=head1 SEE ALSO
L<IPC::SysV> L<Class::Struct>
=head1 AUTHOR
Graham Barr <gbarr@pobox.com>
=head1 COPYRIGHT
Copyright (c) 1997 Graham Barr. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=cut
|
