IPC::Msg

Section: Perl Programmers Reference Guide (3perl)
Updated: 2019-04-20
Page Index

NAME

IPC::Msg - SysV Msg IPC object class

SYNOPSIS

    use IPC::SysV qw(IPC_PRIVATE S_IRUSR S_IWUSR);
    use IPC::Msg;

    $msg = IPC::Msg->new(IPC_PRIVATE, S_IRUSR | S_IWUSR);

    $msg->snd($msgtype, $msgdata);

    $msg->rcv($buf, 256);

    $ds = $msg->stat;

    $msg->remove;

DESCRIPTION

A class providing an object based interface to SysV IPC message queues.

METHODS

new ( KEY , FLAGS )

Creates a new message queue associated with "KEY". A new queue is created if

•: "KEY" is equal to "IPC_PRIVATE"
•: "KEY" does not already have a message queue associated with it, and "FLAGS & IPC_CREAT" is true.

: On creation of a new message queue "FLAGS" is used to set the permissions. Be careful not to set any flags that the Sys V IPC implementation does not allow: in some systems setting execute bits makes the operations fail.

id

Returns the system message queue identifier.

rcv ( BUF, LEN [, TYPE [, FLAGS ]] )

Read a message from the queue. Returns the type of the message read. See msgrcv(2). The BUF becomes tainted.

remove

Remove and destroy the message queue from the system.

set ( STAT )

set ( NAME => VALUE [, NAME => VALUE ...] )

"set" will set the following values of the "stat" structure associated with the message queue.

    uid
    gid
    mode (oly the permission bits)
    qbytes

"set" accepts either a stat object, as returned by the "stat" method, or a list of name-value pairs.

snd ( TYPE, MSG [, FLAGS ] )

Place a message on the queue with the data from "MSG" and with type "TYPE". See msgsnd(2).

stat

Returns an object of type "IPC::Msg::stat" which is a sub-class of "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

AUTHORS

Graham Barr <gbarr@pobox.com>, Marcus Holland-Moritz <mhx@cpan.org>

COPYRIGHT

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.