NAME

       IPC::SysV - System V IPC constants and system calls

SYNOPSIS

         use IPC::SysV qw(IPC_STAT IPC_PRIVATE);

DESCRIPTION

       "IPC::SysV" defines and conditionally exports all the constants defined in your system include files
       which are needed by the SysV IPC calls.  Common ones include

         IPC_CREAT IPC_EXCL IPC_NOWAIT IPC_PRIVATE IPC_RMID IPC_SET IPC_STAT
         GETVAL SETVAL GETPID GETNCNT GETZCNT GETALL SETALL
         SEM_A SEM_R SEM_UNDO
         SHM_RDONLY SHM_RND SHMLBA

       and auxiliary ones

         S_IRUSR S_IWUSR S_IRWXU
         S_IRGRP S_IWGRP S_IRWXG
         S_IROTH S_IWOTH S_IRWXO

       but your system might have more.

       ftok( PATH )
       ftok( PATH, ID )
           Return  a  key  based on PATH and ID, which can be used as a key for "msgget", "semget" and "shmget".
           See ftok(3).

           If ID is omitted, it defaults to 1. If a single character is given for ID, the numeric value of  that
           character is used.

       shmat( ID, ADDR, FLAG )
           Attach  the  shared  memory segment identified by ID to the address space of the calling process. See
           shmat(2).

           ADDR should be "undef" unless you really know what you're doing.

       shmdt( ADDR )
           Detach the shared memory segment located at the address specified by ADDR from the address  space  of
           the calling process. See shmdt(2).

       memread( ADDR, VAR, POS, SIZE )
           Reads SIZE bytes from a memory segment at ADDR starting at position POS.  VAR must be a variable that
           will  hold the data read. Returns true if successful, or false if there is an error. memread() taints
           the variable.

       memwrite( ADDR, STRING, POS, SIZE )
           Writes SIZE bytes from STRING to a memory segment at ADDR starting at position POS. If STRING is  too
           long,  only  SIZE  bytes  are used; if STRING is too short, nulls are written to fill out SIZE bytes.
           Returns true if successful, or false if there is an error.

SEE ALSO

       IPC::Msg, IPC::Semaphore, IPC::SharedMem, ftok(3), shmat(2), shmdt(2)

AUTHORS

       Graham Barr <gbarr@pobox.com>, Jarkko Hietaniemi <jhi@iki.fi>, Marcus Holland-Moritz <mhx@cpan.org>

COPYRIGHT

       Version 2.x, Copyright (C) 2007-2013, Marcus Holland-Moritz.

       Version 1.x, Copyright (c) 1997, Graham Barr.

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

perl v5.38.2                                       2025-07-25                                   IPC::SysV(3perl)