Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

ipc::sharedmem5.16(3pm) [osx man page]

IPC::SharedMem(3pm)					 Perl Programmers Reference Guide				       IPC::SharedMem(3pm)

NAME
IPC::SharedMem - SysV Shared Memory IPC object class SYNOPSIS
use IPC::SysV qw(IPC_PRIVATE S_IRUSR S_IWUSR); use IPC::SharedMem; $shm = IPC::SharedMem->new(IPC_PRIVATE, 8, S_IRWXU); $shm->write(pack("S", 4711), 2, 2); $data = $shm->read(0, 2); $ds = $shm->stat; $shm->remove; DESCRIPTION
A class providing an object based interface to SysV IPC shared memory. METHODS
new ( KEY , SIZE , FLAGS ) Creates a new shared memory segment associated with "KEY". A new segment is created if o "KEY" is equal to "IPC_PRIVATE" o "KEY" does not already have a shared memory segment associated with it, and "FLAGS & IPC_CREAT" is true. On creation of a new shared memory segment "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 shared memory identifier. read ( POS, SIZE ) Read "SIZE" bytes from the shared memory segment at "POS". Returns the string read, or "undef" if there was an error. The return value becomes tainted. See shmread. write ( STRING, POS, SIZE ) Write "SIZE" bytes to the shared memory segment at "POS". Returns true if successful, or false if there is an error. See shmwrite. remove Remove the shared memory segment from the system or mark it as removed as long as any processes are still attached to it. is_removed Returns true if the shared memory segment has been removed or marked for removal. stat Returns an object of type "IPC::SharedMem::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 segsz lpid cpid nattach atime dtime ctime attach ( [FLAG] ) Permanently attach to the shared memory segment. When a "IPC::SharedMem" object is attached, it will use memread and memwrite instead of shmread and shmwrite for accessing the shared memory segment. Returns true if successful, or false on error. See shmat. detach Detach from the shared memory segment that previously has been attached to. Returns true if successful, or false on error. See shmdt. addr Returns the address of the shared memory that has been attached to in a format suitable for use with "pack('P')". Returns "undef" if the shared memory has not been attached. SEE ALSO
IPC::SysV, Class::Struct AUTHORS
Marcus Holland-Moritz <mhx@cpan.org> COPYRIGHT
Version 2.x, Copyright (C) 2007-2010, 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 v5.16.2 2012-10-11 IPC::SharedMem(3pm)

Check Out this Related Man Page

IPC::SysV(3pm)						 Perl Programmers Reference Guide					    IPC::SysV(3pm)

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_CREATE 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. 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. 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. 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, shmat, shmdt AUTHORS
Graham Barr <gbarr@pobox.com>, Jarkko Hietaniemi <jhi@iki.fi>, Marcus Holland-Moritz <mhx@cpan.org> COPYRIGHT
Version 2.x, Copyright (C) 2007-2010, 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 v5.16.2 2012-10-11 IPC::SysV(3pm)
Man Page