info > IPC::SysV

man perldoc info pydoc3 ri search

📛 NAME

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

🚀 Quick Reference

Use Case	Command	Description
Generate IPC key	ftok(path, id)	Return a key for msgget, semget, shmget
Attach shared memory	shmat(id, addr, flag)	Attach a shared memory segment to the process
Detach shared memory	shmdt(addr)	Detach a shared memory segment from the process
Read from shared memory	memread(addr, var, pos, size)	Read SIZE bytes from memory at ADDR starting at POS
Write to shared memory	memwrite(addr, string, pos, size)	Write SIZE bytes from STRING to memory at ADDR starting at POS

📋 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 AT pobox.com>, Jarkko Hietaniemi <jhi AT iki.fi>, Marcus Holland-Moritz <mhx AT 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.

📛 NAME 🚀 Quick Reference 📋 SYNOPSIS 📝 DESCRIPTION 👀 SEE ALSO ✍️ AUTHORS ©️ COPYRIGHT